My view is that the US startup culture exists because of wealth inequality at the $1-$20m net worth level. Wealth inequality is socially incentivized at that level because of the lack of a decent social safety net. If you don't save money then at 50 you may end up homeless on the street due to bad luck. But if you don't get bad luck then you end up at 50 with a large amount of money that you don't have much to do with. So you start investing some in riskier things because who cares.

US founders not from wealthy backgrounds can often get $500k from friends and family. I doubt those in the UK can do so.

There's massive massive social costs due to this in the US so be careful what you wish for.