Email is just dead as a tech. It's no surprise nobody uses it for sensitive content anymore but instead just uses it as a notification service ("Please log in to our portal to read your message").
I don't personally like bitwarden either because it uses a master password, I prefer "pass" which encrypts each password with your GPG key (which can be stored on a yubikey for hardware security). But yeah self hosted bitwarden is a good option too and very popular.