The police gained access to the IP address because Swiss authorities chose to cooperate with the French government

We’ve seen this several times now. Proton is subject to Swiss law, just like every company in their respective countries. You choose Proton because Switzerland has the most privacy protections of any country on the planet (for now).

If you want private communications, don’t use email. In fact, if we could all stop using email entirely, that’d be wonderful. There are hundreds of truly-private alternatives, many with no company involved at all.