Moving to a country where crypto gains are not taxed is a very good idea in such a situation like this, but before you choose doing this as your final decision, you have to sit down, take a piece of paper and a pen, and maybe a calculator and calculate how moving to a new country will cost you, not just your flight ticket and other logistics expenses but also how much it will cost you to settle down comfortably in your new found country..
IMO, it isn't a wise decision.
AFAIK, French tax authorities are aware of people moving abroad to evade taxes.
If that is the case, and they determine the move is primarily for “
tax avoidance,” while you maintain strong ties to France, they may still consider you a tax resident for French tax purposes.
This could mean your crypto gains remain taxable in France even after your relocation.
If you truly need cash, you might have to accept a 30% loss on your holdings in exchange for a hassle-free move to another country just for that money.