just about every game you play has it, even 3D games, it's just not noticeable in 3D bc they fine tuned it (velocity and/or raycast based, slow movement does not trigger coyote time/jump buffer)
it's sticks out in 2D for sure
yes in 3d game its harder to notice it,... :)
for jumps i just think: that we can make jump not so hard, just a bit fun... it doesnt need to be like barly posible, its just need to be not so easy when on higher levels in game :D but not nearly imposible so then no need for coyoty time :D but yet again now people are use to it, and of course evry gamedev can make as he feels that is the best :D