With an American tech salary of $200k/yr, I can pay for all of that (health insurance, student loans, etc.) and still sock away $100k/yr in savings. That $100k is more than enough to build up a massive nest egg which will provide for me better than any pension or unemployment insurance would.
If you play your cards right, you can be financially independent after about a decade of working in the US tech industry. Your entire working career could be only 10 years. That would be insane to imagine in Europe, yet you think France has better quality of live?
You mention having more vacation. I know plenty of people who switched to contracting in the US so they could have more time to focus on startups and hobbies. They only work maybe half the year, yet still make more than developers do in Europe.
European developers are underpaid. Full stop. You could dramatically improve your financial circumstances by getting a job at a US tech company (though the visa situation makes that challenging).