It's not compromised.
Just be intelligent how you use an email. Zero knowledge encryption means that even proton cannot access your email content.
They have an onion site where you can open an acc...
Non PGP encrypted mail (99.9%) is only encrypted via transit by TLS V1.3 at best. Proton has no choice but to decrypt your mail as they recieve it, then Re-encrypt with your PGP key secured by your proton password. They can see all your mail, as a fault of the insecurity of the SMTP protocol. It's only Zero knowledge after they re-encrypt, you have to trust them not to scan 100% before they encrypt.