[throwaway22032]

This is to some extent a kind of tautology, though.

There is more money available to chase housing in urban areas because it's where most of the jobs are due to network effects, so if you are a labourer you gravitate towards that (as you say, it's a commute thing).

It's not necessarily intrinsically more desirable. If you gave the average person 5 million quid I don't think they would choose to live in Central London.