Why do you think AA suck ? It’s the chemistry, not the standard size, voltage or swappability right? 18650 and 21700 also have those assets. Some modern devices let you swap 18650.
Every chemistry outputs a different voltage and requires different charge controllers. So sure we could have created a standard lithium size but it would have just locked us in to one chemistry again which will eventually be obsolete. 18650s are also too bulky for most applications. Usually you want flat rectangles. Another benefit of the proprietary batteries is they can completely fill the space available rather than being constrained by the standard.
Swappable proprietaries are still better than not swappable at all. For my previous phone I managed to order an external charger and several replacement batteries.
My understanding is that it's a poor form factor for lithium ion - which operates at higher voltages, and thus needs an extra voltage regulator to step them down to 1.5V if you're packing them into the AA format (adding cost, reducing capacity, & introducing conversion losses.)