I think waiting until screen readers adopt technological affordances to start using those affordances is putting the cart before the horse. One could ask why a screen-reader-tech maker would bother paying attention to tags no-one uses—might as well put as much semantic information out there as we can, and let different people consume it in the ways that make most sense for them.
It’s an impossible situation. We are expecting website owners and screen reader companies to come to some kind of consensus without ever collaborating or establishing a standards.
And just expecting that vaguely guessing what the other wants will work.