It has been said previously but I'll add this as well:
So now you have two problems.
- How do you balance AST's card system, Divination, Mug (previously TA), Chain Strat? Benediction - a full heal? Tank Invuls? Battle Litinany? Arcane Circle? Any other party buff I missed? How do you balance a healer's lv90 kit in lv15 Satasha without the healer being bored when they are already bored now? (see: Healer complaints #1337) How do you balance WAR's healing?
- How do you balance the effort a lv50+ person has to put in vs a lv15 sprout? For instance, at lv15 currently as a Tank I have a 1-2-3 combo. Taking my GNB for instance, I'm at lv90 with my full Gnashing Fang combo, Double Down, 3 cartridges, and Hypervelocity. ...And doing all that I'd be dishing about the same damage as a tank with a 1-2-3 combo? Or... if I'm NOT, then the even if the damage is scaled down the bosses and trash are going to be cut down much faster?
You can't just remove skill sync and "rebalance numbers" in a game that never was going to do that to begin with. That's an overhaul of ARR porportions tbh.
Edit: I also forgot to add the dungeons weren't balanced around every party member having AOEs either. Some melees don't get theirs til their 40s and beyond and healers don't get theirs until 47? or around there. And WHM has HOLY a stun!