More or less but is what's available, same thing goes for the continent, a developer for Amazon in Berlin would be making 60-65K euro's.
The UK used to be a big upgrade even outside of London due to the relative strength of the currency(especially during the Euro crisis), but the EUR and the GBP are almost at parity these days so that's gone (if you are making 50K GBP it's 59K US, if you are making 50K EUR it's 55K US these days).