If my salary had been my only or even my main objective, I would have taken a very different route in my career. Sure, for some people it is, but there are other factors as well. But if you're from the UK, young and independent, and money is your main drive, what's keeping you from moving to the US, at least for a couple of years?
Getting a visa is incredibly difficult, with the easiest route being working for a US firm in the UK and transfering to their US offices, but at which point you're already one of the lucky few to score a US job in the UK and are probably paid well enought that uprooting your life doesn't seem worth it.
> what's keeping you from moving to the US, at least for a couple of years?
Visas. US has a very very weird visa system that really hates skilled workers.
The green card lottery?