Honestly i get hit by AOO quite often ... but its usualy bcs i didnt notice that my character need to move little bit to cast/shoot, and then s/he get smashed ...
So i would not say that with disengage for everyone AOO is completely wasted ...

But, over and over ... i agree with OP.
I would also appreciate being able to jump without need to spend Bonus Action.
And i would certainly not mind if Disengage become ability of certain classes. (If i get that right)

I liked original spellcasting system more ... frown

Anyway ... i cast Eldritch Blast!