I presumed screen readers had some kind of standard in the way they interpreted things. The standard allows the user to choose which screen reader they want.

I presumed screen readers had some kind of standard in the way they interpreted things. The standard allows the user to choose which screen reader they want. Letting the screen readers interpret things however they want seems likely to end up in a situation like browsers. Horrible shims everywhere to handle the idiosyncracies of how each reader interprets things.