Brit here. Garbage. I have simply told the mixed US/UK company I worked for that they had no rights over a personal project of mine and they were cool with that. By your dismissive, failure-assured attitude I can guess that you've never tried.

Europa is a big place and how things like this work varies a lot.

Spaniard here. Definitely negotiated IP terms for my current contract :-)

I think it has to do more with the size of the company.

Good luck negotiating that with a FANG, smaller companies won't give a damn (unless they have a dumb HR department who doesn't understand how hard hiring devs is)