Rentysomethings is about right.

That's what I would be were it not for a previous much more lucrative job, a partner who earns far more than I do and an inheritance.

It's not just about those earning well above average earnings not being able to get a place of their own, although there is that; it's also about those on below average earnings.

Another effect of high house prices combining with house ownership being desirable for various reasons is of course that both partners need to keep working.