Proton a few years ago disclosed the IP address of the user of a certain mailbox upon request by LEA. That was enough to get the person found and arrested (I don't remember what the case was about). They HAVE to comply with these requests, but they DON'T need to log/retain those info ETA: and I was wrong, thanks @Cheradenine to set me straight. But I think the point still stands. I don't want to be ALWAYS be tied to a VPN, there are some scenarios where I can't use a VPN.
That was the moment I decided to selfhost my email server.