Why isn't full controller button remapping a thing?

It shouldn't be that difficult to essentially remap the entire controller button layout.

This has been a problem the entire time.

Why can't I choose what the ultimate ability maps to? And on that not, why can't I map abilities to a combination of buttons.

Tac on L1, Ult and L2 and grenade on L1+L2 seems interesting.

This seems like a problem that should have been solved about 10 seasons ago.