I don't trust Proton at all, and Obsidian is a nicer experience for this anyway. I had a ton of old notes, and now that a new owner is taking them all, it's time for me to delete my account and move on.
Can you articulate why you don’t trust Proton? From everything I know, they have a stellar reputation and have been around since 2013 with no end in sight.
If you trust Proton, you trust that they'll remain e2ee securely. If you don't trust Proton, you don't trust that they'll remain e2ee securely. I don't trust Proton and actively avoid their products.