The traditional Face, however, has no chance when social adepts are around. The adept does everything the face does, and better, without a downside. That's a balance problem and eliminates an archetype, so, it's something that I'd like to address. Probably couldn't be dealt with until the distant future, but, 5th ed is all about "Choices have costs" and "There is no one best way", so, having a clearcut "This is better" is bad.
Boring meta crap incoming.
Four flavors of faces, Mundane, Adept, Mage, Mystic Adept. Mundanes and Adepts have less access to Charisma buffs, pretty much Novacoke and Narco is the way to go for them to get Charisma buffs. Mages and Mysads can usually find a way to sustain a +4 Charisma buff if they want.
Skill buffs, Adepts and Mystic Adepts have access to powers that increase skills that Mundanes and Mages simply don't have access too. It's not that Mundane characters can't get bonuses to skills, its that Adepts have all the same options plus several other, relatively cheap options.
IMO you'd need to introduce a cyber/bio/whatever Essence using Augment that increases Charisma. You probably want a couple of options, one that stacks, one that doesn't, ect, ect. Choices with costs.
IMO the other thing you'd need to introduce is an Augmented Skill Cap. This way an Adept can't stack a Mentor Spirit, Increase Skill, Adept Powers, Fancy Suit, Positive Qualities, ect, ect. Keep it consistent with a +4. Mundane Faces can easily hit a +4 in a skill, give them access to a Charisma Augments and you've now got parity in dice pools at the top end. I can't think of what else an Augmented Skill Cap would break. Physical Adepts probably? Anything else that gets more that +4 in a skill is a corner case. (Catlike, Reflex Recorder, and Chameleon Suit for Sneaking, honestly can't think of anything else off the top of my head?)
Teamwork buffs can stand outside the Augmented Caps to give you a mechanical option to stack a buff without hitting the Augmented cap.
MySads and Mages will still likely be "Better" as they're full blown Casters/Summoners still. But you can put together a Mundane Face that has comparable Social Skill dice pools and is a Samurai lite as a secondary. Then you've moved your balance issue back to Mage vs Mundane, at least at a 10,000 foot view.