[agentdrtran]

Matrix is probably the closet alternative but it's harder to use than Signal (lost your password? say goodbye to your messages!).

[_wldu]

Yes. Without an email or phone number there would be no way to do an account recovery, but perhaps some other clever solutions (allow some of your contacts to reset for you, or sign a message with your key, etc.) may be an option.

[pessimizer]

That's a feature. I don't want my account to be recoverable without my password.

[agentdrtran]

I understand that use case, but for most people that's horrible as they don't take care of their passwords very well.