Having done exactly this for adding accessibility into a crypto wallet in the past, (yes crypto wanted even the disabled), it is plainly obvious why this is not standard.

It is an absolute train-wreck trying to get everything to work and for the overwhelming majority of products it isnt work the effort. It isnt like you put a wheelchair ramp up and are done. It is a constant battle with every change.

It is just another one of those things where the minuet minority suffers. Now if a company got some tax write off for it, that would change things.