It's not only that the rate is adjusted for locale but that the disparities in USA are much larger. In USA a very senior engineer at a FAANG in California will

It's not only that the rate is adjusted for locale but that the disparities in USA are much larger. In USA a very senior engineer at a FAANG in California will earn 20x times more than a junior engineer at some small midwest company. In UK a very senior engineer in London will earn perhaps 4x that of a junior engineer in Wales. In USA "pays very well relative to other professional-level jobs in the local labor market" will often mean a compensation that's double or triple of those other jobs; in UK "pays very well relative to other professional-level jobs in the local labor market" would imply a 20% or 30% difference. That makes a meaningful conceptual difference.