I'm sorry, I'm Australian and studied and worked in Australia. I spent 4 years in SV, and now founded a startup in Europe.
Even after the Covid issue has played out, I'm convinced SV will still be where a passionate technologist can optimize their impact and lifetime earnings. There's just nothing that can compare to being surrounded by so many smart people who share your interests.
I've heard stories about the dotcom crash, and how it was awesome because everyone who had no business being there left. You just had the geeks that wanted to build stuff for the sake of building stuff, and it turns out there was still plenty of money floating around after things got going again.
Europe has laws which makes hiring people risky and expensive. And even if you do become a top earner, expect to pay 50% in taxes (+ 25% VAT). It's hard to fathom individual engineers would be able to save enough to have the sort of financial freedom to bankroll a company while still in their 20's.
But don't worry, there are government grants for you! Just be prepared to spend 1/3rd of your time dealing with paperwork and hourly reporting of what you did on a day by day basis, all for 50k here, 40k there. I feel these grants are designed to be demoralizing and the startup equivalent of unemployment benefits. And then you realize that almost all R&D in Europe, from startups to multinationals, is subsidized by EU funding schemes and mountains of paperwork.
Don't underestimate how good SV has it with the "I like you and your idea, here's $1m and come back next year and tell me if it worked".
</rant>