Speaking from experience as a postdoc, we earn less for sure, but from what I can see a postdoc in the US earns about the same. In the rest of Europe things are a bit different. At the extreme end, in Zurich you might earn 100k CHF as a postdoc if you're lucky (but you pay 30EUR for a pizza). Even at really top-tier places like TUM, you're going to be on 35-40k EUR.
A typical professorial scale in the UK (most universities publish this information publicly) ranges from £60-120k.
You have to realise two things. First, that FAANG are crazy outliers. Second, that UK universities are publicly funded and with few exceptions, justifying six figure salaries from the taxpayer is difficult. A lot of professors make good money on the side by doing consulting.
I believe this is different in the US, as a lot of universities (like Stanford) have huge private endowments. I'm not sure how it works at places like Oxford where the university owns half the centre of town.
A senior engineer in London or a tech hub like Cambridge might make six figures, but that's after several years probably. For engineers, there are much higher salaries to be found elsewhere in Europe in places like Munich.
