Yes, completely agreed. One concrete example is that battlemaster should get new, more powerful manoeuvres at higher levels. That they just choose from the same pool at all levels is silly. It's like if casters just got more level one spells at higher levels.
"But if the battlemaster did more damage, then it would make the simple subclass, the champion, look useless."
"What if the higher level maneuvers did moe than deal more damage?"
"But if the battlemaster did more of anything but damage, then it would make the simple subclass, the champion, look useless."
"Then the champion and battlemaster shouldn't be the same class so they wouldn't share the same base and be in competition with each other. This wuld lower the arms race and allow martials and casters to growat the same rate."