Does the op really hate martial classes so much that he thinks that caster classes need to over shadow them even more?
Xeviat has never shown that inclination that I've noticed.
However, when trying to balance similar classes, the path of least resistance is generally to power up the ones at the bottom of the heap. When comparing full casters, that's probably the Sorcerer. That there are other, dissimilar classes, that are just going to be left further behind by such a power-up isn't exactly relevant to the goal of balancing the first set of classes.
It's actually worse than that, because some of the ideas floated are to power-up both the wizard and sorcerer or power up all the casters!
Why do so many want the terrible mistakes of 3.x to be repeated?
75% of the playability of 5e is because of nerfing the utterly godlike 3.x casters into 'reasonably overpowered'.
I think you answered your own question. ;P
Seriously, though, picking back up some of the things 3.5 did 'right' might be an idea. Make prepped casters Vancian again, needing to prep their spells in slots instead of casting spontaneously. Spontaneous casting because a real advantage of the Sorcerer again. It might not close the gap entirely, but it could at least narrow it, without powering anyone up.
Some other things that might be worth bringing back: AoOs for casting in melee, allow ranged attacks to interrupt casting (perhaps as a Reaction), random starting spells, wizards needing to find spells to add to their book rather than just learning them automatically as they level, save DCs based on slot level rather than caster level, proficiency applying to more saves, % magic resistance, etc...
But powering-up Sorcerers (and Bards! really?) seems unnecessary.
And giving away the one unique toy 5e Sorcerers got to all casters? Seriously?