Engineer salaries in the uk

hi i am an american chemE graduate looking to move to the UK. Ive looked at salaries for engineers and they seem really low. You would be lucky to get £30k when you graduate ,£40k mid career and£50k late career. In the US, even recent graduates like myself can find jobs paying in excess of £40k. Mid career, we could expect around £65k and late career , £100000 wouldn't be a stretch. Even jobs in oil and gas in the UK cannot compare to less lucrative fields in the US. So how come Uk engineers get paid so much less? To me it seems just an engineering thing. Doctors, lawyer and bankers seem to make so much more than engineers over there.

+ how come you guys dont move to other countries?