I think he assumes that a certain quality of discourse will be maintained (or reappear), but it's not clear that that's true any more.
It might be true that the current cycle of anti-intellectualism will continue beyond our lifetimes, but we’ve recovered from worse.
However, when you're in the middle of a revolution you don't really want to be there.
Basically, probably the next generation will be able to tell how bad things really were and if by their time things are truly better.