Prior to Brexit the go to place for tech in Europe was London, UK. Likely Google would have expanded their offices there, and probably move them where everyone else is. From _the_ place to be London is now the place to avoid. 80% of the brightest people I know have left the UK. What we are left with is with those that need at least two more like them to get a job done.
The UK still gets more tech investment than France and Germany combined, and I wouldn't surprise me if London got more than either of them. Like, Brexit was stupid and harmful but London still dominated European tech.