This is interesting but I think it's just a matter of time before the dam breaks and all the tech companies with a UK presence start increasing salaries to get more competitive. The same thing happened in NYC around 2015-2020. At some point money talks and the bullshit starts to walk.

I know someone who is moving from NYC to the UK to run an engineering team at a FANG company. He'll want to hire the best engineers and be willing to pay for them. And I know he wouldn't have taken that job if it didn't come with a big pay increase.