I also don't really care for the back buttons as far as I'm concerned. Maybe I would if it would let you bind anything to it like on keyboard, but since it can't be another new function, it's just a shortcut for an existing button so I don't really see in which games I could use it.
It would be nice if you could bind new commands to that, like in RDR 2 for example, when playing with a controller it's awful because you have to spam the A button to sprint, even with a horse, while on keyboard you only have to hold shift and that's it, so having shift on a back button could maybe help, although I don't really know if it would work well, like the game would recognize keyboard and controller inputs at the same time, it would probably glitch.
So for me it's really about finding a new decent regular controller.