I would love to see an app/overlay that displays what each option is during the call. Some system where you don’t have to listen to the whole list of “press x for y”.

I have no idea how to go about implementing such a thing, but it would be cool if someone picked up the idea and ran with it.

Android does this fairly well for me - it will list out the options as they are spoken, and you can click on them directly to type the number. I believe (but haven't seen this recently) it will pre-render the options before they are read if it has knowledge of that phone tree.