One thing is true. Google can disable your account but you can keep all data locally using POP3/IMAP for free. You can use GPG with Gmail with your private keys stored locally. You can encrypt Subject with GPG in your Gmail. Yoy can use your Gmail account with Delta Chat. You can forward your e-mails and so on

Users of ProtonMail can only dream about it.

Thr bottom line is. Gmail is better than most of "privacy and security" oriented providers like Protonmail, Tutanota etc.