By the exchange rate right now, 50k GBP is around 65k USD. If you want to live within (say) an hour reach of an office, you’ll have a much easier time doing that in the London metro area with 50k than you will in the Bay Area with 130k. This is before you even consider taxes and healthcare. High quality groceries also substantially cheaper in the UK. A new wildcard is the price of energy, which looks to have gone up considerably in the UK since I left, though.
Neither would be a comfortable position, and you wouldn’t be in danger of being able to buy a house absent other income. All in all though, if they were my fixed options, I’d take the money in London.
Houses, even small ones, in zone 1-2 are now prohibitively expensive, but if you are willing to move further away there are options.
But yeah, overall it's highly personal depending on personal circumstances than anything else.
Regarding transportation, I have been living here for 13 years and still don't own a car.
I still wouldn’t compare 50k GBP to 130k USD.
While this does have a partial truth to it, the examples are delusional. How can anyone compare 50k GBP to 130K USD?
I have lived across the USA, EU, and Asia; but such comparisons are heavily personal situation dependant. The calculations would differ for single vs family as well.