> expecting anything more than that from most drivers is a lost cause

I can't speak to the area you live, but where I'm from we get along just fine. Yes sometimes you still get the odd unfamiliar driver that doesn't understand them, but for locals there's a critical mass where roundabouts stop being avoidable and you adjust.

See also: https://www.iihs.org/news/detail/safety-at-two-lane-roundabo...