L2 is used for Jump with literally every character. I've gotten so used to it that I can't unlearn it. And then there's the universality aspect. I need jump on L2 for genji, and there's little reason not to have it with certain other characters that have free slots there. But after a while, especially if I have a long session with Genji, my muscle memory didn't differentiate between characters and kept trying to use L2 to jump for everyone.
In the end, I like Jump on L2 too much to move it now. It lets me feel I ahve more control of the character. Some characters this isn't as much a benefit to (Reinhardt for example), but it messes with my head if it's not there, so I basically need it to be.
As a result, I've had to map atleast one ability from every character elsewhere. And for the most part, it's worked fine, since nearly all characters have one non aim dependent ability I can just hit. Except for Ana.