The concerning thing, in my opinion, is that the poster linked by OP seems disillusioned as to the standard of living in the UK. They specifically mention being paid £55k as being equivalent to $100k in the US. It isn’t.
£55k in London is about enough to rent a place and live ok’ish on your own, and relatively comfortably if you have a partner whom is also earning a salary in a similar bracket.
Rent on a 1 bedroom flat in zone 5 is costing £1,500 as a minimum. You then have council tax which is about £200 a month (soon to be increased). If you travel to the city to go to the office that is gonna cost you at least £50 a week, more if you need to go everyday. Your utilities will cost you at least £100 a month and food, without takeaways is also going to cost you about £50 a week.
All the costs above are lowballing intentionally and do not factor in things like the inevitable lunch coffee and after work drinks, albeit non alcoholic. The reality is that the UK is becoming a much less livable place and that the cost of living/energy/whatever comes next is always passed down to the average person.
I will not be surprised to see an exodus of skilled workers over the next decade. I personally have set a 5 year target for leaving the country personally, which is sad. My partner has noticed the change herself and is equally as sad that the reality is she will need to leave (after working to acquire citizenship) in order to have a proper chance at buying a home and living a happy life.