Same here, some of your southern neighbours also have unions on IT, as a union in general covers specific industries, regardless of what job each person does in the building.
As a tip for others as well, even without an union it helps to be aware of the country labour laws even if superficially.
Most tech companies give paternity/maternity leave. There is the WARN act and most companies provide severance. Are the packages always great? No, but I don't think equivalent in Europe are that much better. Public transport? That's your preference and lifestyle, I don't think that factors in here. Most tech companies provide decent insurance and don't require being part of some socialized wait-list system. And the salaries are quite a bit higher and without the Byzantine level of taxes. I think you might want to analyze it a little more.
Do this comparison both ways and factor in what you pay in addition for American high-stress/low-quality healthcare, college, retirement, etc. If you’re on the higher-end of the SV tech salaries, you’ll probably still come out ahead but for everyone else even Denmark tends to be cheaper.