It would be way more useful on NES (and Game Boy) because some idiot decided Switch B was NES B and Switch Y was… nothing at all.

That’s not how thumbs work. You can’t have your thumb rest on both Switch B and A like you could on a NES (or GB) B and A, the orientation is wrong for that.

On a SNES button pattern, you’ve got two diagonals, B-Y and A-X, with B-Y being the important default, natural one and A-X the alternative options for which you slide up with your thumb.

At least A-X works on switch online NES, but B-Y should too. They’re the basic button pair everything else uses.