They'll switch to async communications for everything, and ideally have a bot that answers Mm-humm like a psychologist on his chair.
More seriously, the solution is to move to a flatter org, but that's a drastic change with unknown consequences for most companies.
I feel like managers should be able to contribute. Managing a good team isn't that hard, though managing a bad team (or a good team in the midst of a ton of bad processes) is a nightmare.