After thinking about this for a while now... And I think for me, simplification has been at the root of every disliked change...
Be that the thematic and system changes of UMT, The current dice meta of Pool VS target VS limit...
Every step that been to simplifiy the game, and has borked a part of it, or created new issues...
As much as people rail against overly complex rules, it seems its these complex rules that adds the depth that many people seem to crave. Just reading a few threads here about 6e and 5e and the issues people seem to have, most of the issues seem to come to a too simplified, or a "dumbed down" rule.
While I don't have any great thought out ideas, nor a fully developed system, I will touch on a few things I think "got broken along the way" and what might be a possible solution.. (or, just a
really bad idea. Who knows. ).
SETTING.
Right now, The setting of shadowrun is in a bit of a an identity crisis. While its definitely Sci-fi, and futuristic ... Is it Dystopian? Is it Transhumanist? Is it something else?
Originally, the game was very much Dystopian. It was all about the little guy against "the man". Corporations ruled the city, and despoiled the planet in search of every great profits, all the while stepping on the everyday citizen...
Now, it would be easy to point the finger at 4e (Fanpro) and say
this was it; the moment that the confusion got added! But, that would be ignoring some of the things (admittedly again, as mostly plot points) that got added in with the Otaku. And, it was 4e that saw the first full scale intrusion of Transhumanim into Shadowrun.... And that would be the Technomancer. (and
NO. The technomancer has not been around since 1e. Back then the term was used as an adjective for Decker. Not rehashing that argument again - its on the forums.)
Now, in principle, I don't have a problem in with technomancers as a whole. they are an interesting concept - for an other game. For Shadowrun, they add in a thematic and setting Break. Let me explain:
Originally, as I said above, the setting of Shadowrun was a Dystopian setting, with an oppressive society designed to keep people down and in their place. And, in order to
rise above "The System", and to survive one had to either be born with an advantage, or sacrifice for that advantage.
Magic was one way to power, as magic was a wild card that could not be easily countered for. It couldn't be sensed (except for by other awakened), it couldn't be controlled.
(its a natural phenomenon), but it was extremely rare. And, it really didn't interact well with technology. (like at all!!) And people feared it, thus over reactions to magical
displays were common (AKA "Geek the Mage First").
The other avenue to gain an edge, was to to change the body, through drugs, genes, and cybernetics. But this came with a cost, the more you used or indulged, the more of
your Soul you lost... Until one day, your Spirit decides it wants to be somewhere better, and you die...
The game system was set up in such a way that if you went awakened, you paid an huge opportunity cost (starting resources), faced dice-pool modifiers for Social
interactions (As most people hated and feared you), were target #1 for combat action, faced more dicepool interactions for technology (anyone remember the
DATAJACK?!?! Anyone? yea... more on that later...) or, just couldn't do anything technology wise.
If you went with Drugs, Genes or Cyberware for your advantage, you faced different problems. If you dipped to far into the drugs, genes or cyber, people didn't like you.
(you got a TN modifier after [2] or less essence) If you tried to push your body too far, you died. You also didn't interact well with magic. But there was no general social
problems for having a bit of Cyber. To the police, you where just another nobody.
Technomancers, however, break this game concept. And with them, we have seen some really big issues introduced and a proliferation of magic and tech actually working in harmony (looking at you
ANALyze Device [Can you tell how i feel about this spell

]).... From magic and tech not working at all, to wizards that only work with tech...
NO.
Just NO. Not even going into how, in a setting with Corporations with a graveyard of skeletons in their closets, or Secret Orders that want to remain secret... Technomancers not only break the fundimental "laws" of the setting, they just wouldn't survive in the setting with the acceptance the have....
OR the system would adapt to the point to render their abilites moot....
And I think the original FanPro writers realized this very problem after they included them into the game... which is why everyone after Fanpro has pretty much been left scratching their heads going "What the fuck do we do with
this mess???" Because, really, think about it...
Somehow these idiots are receiving, interpreting, and transmitting machine code! And if they are receiving, interpreting and transmitting machine code then NO countermeasure program, firewall, or even method to detect them could ever be used. Why? Because they are interacting with the data before its been turned into a program and executed... They are Neo/the soul the Matrix... Which means they can NOT be kept out of anything!!! And, if they are NOT receiving, interpreting, and transmitting machine code, then a simple change of the algorithm and codex structure would render them useless. (like speaking Esperonto in Japan...)
They just do not fit within the world that has been created, and have been shoe horned in. At the determent of both the Hacking and rigging rules. (Because Technos have to be fit into both of those rule sets too) And at the determent of the setting.
MAGIC
Speaking a someone who has played a Mage since 1e.. I can tell you now, 4e and 5e where the best time to be a mage! (No comment on 6e, as I have yet to read it) Seriously! The kiddie gloves came off in 4e and 5e and it was now time to lay the magic smackdown on EVERYTHING!!!
Which is the problem.
So much got "simplified" from magic that you could rename the game Magic run, and you would probably not get any complaints. Magic in 1 to 3e was powerful, true, but it also took a fair bit of juggling and forethought to get it right, or you could end up screwing yourself over.
Originally, when a mage went to learn a spell, he not only choose the spell, he also learned the FORCE of the spell... And to change the force changed the target number... this left mages in a quandary... Do you learn a buff spell at max level and suffer all that drain, or do you learn it at low force and lose out on some effect.
Now, you just learn a spell.. cast it at whatever force you like... and spend a pocket of reagents to buff it....
Mana Spells and tech were a strict "no go".. If the spell was mana based, it did not work on technology. Period. If the spell was physical based, then its effects were reduced depending on the target. Casting a fireball or ball lightning on a drone or vehicle saw the spells effectiveness drop a whole power level. (So a spell that was going to cause a Serious wound, caused a moderate wound... Or.. 6 boxes of damage reduced to 4 Boxes of damage out of 10 total) If you wanted to harm technology, you had to learn a specific spell to do so.. (Wreck), and there was a separate version of the spell for each class of vehicle and object! (so.. Wreck Gun, Wreck Drone, Wreck Vehicle, etc)...
Now... Ball lightning. all day every day. Its the only way.
Spirits and Elements were two separate things, summoned by two separate people and behaved entirely differently. SPIRITS where summoned on the fly by Shamans and were tired to an area not bigger then a few blocks. Meaning you could run away from one if you choose to. ELEMENTALS were summoned by mages in a ritual, cost reagents, but could go anywhere...
Spirits/Elementals and Tech: It was the disconnect between magic and tech that gave a spirit his immunity to normal weapons. Both could be hurt by a bare had and a force full personality..... (Again.. Technos shoot this concept out of the water...)
As part of the trade off for a shamans ability to summon on the fly, they couldn't discreetly cast spells thanks to the Spirit Mask that formed when they cast..
BUT NO... too complex... ditch the subtly the complex rules gave us... Mages, Shamans.. same coin.. don't matter much

TECHNOLOGY
Something really silly and simple trick they did back in the early editions was make one piece of cyberware the catch all for all ware... The Datajack.
This simple piece of inexpensive ware ($500. 0.25 essence) was the gateway for just about every other piece of ware out there.. and served as a limit on awakened.
The Datajack, was the commlink of its day... without the datajack, your smartlink sucked, you couldn't 'jack into the matrix or your drone, And good luck making a phone call or surfing the matrix!!! Some simple implant was the interface to Cyber tech and acted as a limit to awakened, because while it was cheap, it cost you a full point of magic for no gain! it only allowed you to access the other cyber, which cost more essence and ware.... and thus Burn out was a real option... and not just a thematic one like it is now...
Who gets a datajack now??? what exactly do they do?? (nothing. nothing at all)
So, in the rush to simplify, they broke datajacks, and the built in limitation to awakened and tech...
CHANGES
Things I would do differently? I would bring back the combat, defense and spell pools.... and utilize them in to the dice pools...
For example a combat pool might be (STR + REA + INI)/2. This pool of dice could be added to as you wished to a attack rolls over the course of a Combat Turn (so multiple initiative passes) until the pool was exhausted.
Defense pool would be similar and used to augment their defense rolls in the same way was the combat pool... But would be smaller to start.. say (Body + Ini + Rea)/3. This would place of emphasis on armor soak and body soak, as opposed to simply dodging... (bullets travel 1000s of feet a sec.. most combat breaks out in under 100ft... yea... Antons of time...)
Spell pool for spell casting as well, same type of mechanic.
All rolls would be a mix of Pool dice (Pools are made from attributes) and Skills... this keeps skills important, while still allowing attributes to have an effect, while limiting "broken Munchkin" builds out of effectiveness (So.. No trolls with max STR and BDY, and 1s everywhere else being effective combat monsters... leave them on the couch with the rest of the human potatoes)
I dunno... Maybe its the beers talking..