I would not be a fan of this.
Sorry I misunderstood.
I was wrong in in understanding what you were suggesting then. I don't see how you don't see what the others are saying then. I thought that MAYBE it was a difference in what you said vs. what they understood you to be saying, but if they are right...then I think they are saying why simply higher ability scores (limited to 20) are not really the solution. It doesn't do anything really better as long as they are still limited to 20.
All classes then get feats easier, not just martials, spellcasters STILL have more options and don't even have to roll to see if many of their spells are successful (vs. martials always needing to roll for an attack), and once a spellcaster knows the stat to target, it becomes easier for them just to target the weak saves to be more succesful than martials in whatever they decide to cast. I don't see your solutions really solving any of these disparities.