The UK isn't a great example, because most MPs - especially in this parliament - are basically filler, with little or no real agency. They were parachuted into constituencies by the Party HQ, with no local connections, often against the wishes of the local members.

It's a nice job, but you have to toe the party line to get it.

There are still exceptions, but the days when the core of the Parliamentary Labour Party was made of people from all backgrounds are long gone.

The UK is actually run by a handful of industries - especially finance, defence, and fossil fuels - and there's much less diversity there, token or otherwise.

School/university diversity only goes so far to solving the problem. Outsiders will still be left out of the existing privilege networks for economic reasons - most people can't afford the annual round of skiing and yachting holidays in prime locations - and for social reasons, which include a lack of confidence, lack of familiarity with expectations and traditions, and outright bullying and abuse.

This isn't an argument against diversity, it's to make the point that breaking down the gatekeeping has to be the start of a broader process. It's not a definitive solution in its own right.