Once you decide to go to "Europe" then the question becomes why the UK and not somewhere vastly cheaper like Romania or Poland. Wages in the UK are lower but wages in eastern Europe are much lower still.
Not as true now as it was even 2 years ago. Slovakian wages are reaching parity with the "West" of Europe, and Romania is climbing as well.
Until the war, Ukraine was also climbing that same ladder. And when the war is over, they will soar. Their skills are at least the equivalent of any developer I've worked with, their language skills are impressive, and their analysis and design skills are as well.
The UK has lower salaries than west coast US and a large pool of suitable workers.
Big tech has a presence but why haven’t they moved their main operations to the UK?