Perhaps it is local familiary. Living in Oakland and working in San Francisco I made $175k and was able to save $4,500 per month after all of my living and familial expenses. When I’ve spoken to companies in London they seemed to max out around $100k.
Whenever I looked at apartments online trying to find an equivalent lifestyle (30 minutes door to door commute, nearby parks and restauranta, 1 br 85 m^2 with good amenities) the rent always came out about the same as what I was paying ($1,840/month).
The difference being home in Oakland My hood was mostly single family homes with yards (and a few yuppy apartment complexes like mine). In London everything within that commute range seemed to be a concrete jungle, and I couldnt figure out how to find an equivalent neighborhood withot really going far away from the tech companies.
Whenever I visit london my dollar never seemed to stretch far and food / groceries / transit felt reallly spendy.
London pubtrans is clearly better than anywhere in the USA, that goes without sayyng, but was also more expensive (if I went to the office I think I paid $4 each way for the transbay bus, with a 5-10 minute walk on each end of my commute).
It’s a great city (except for the traffic. I would be terrified to ride a bicycle there), and one of my favorite things to do in life is smoke a spliff and walk down the camden locks trail.