[Normille]

That works as long as you to know the email you signed up with and have forgotten the password. But what if it's the other way round?

I'd imagine most web savvy people these days have several email addresses and lots of us will use disposable emails or tricks like adding '+something' to our emails when we sign up.

I've recently run into this problem on a couple of sites [I'm thinking Trustpilot and Mastodon but could be wrong], whereby my password manager had saved my login name and password but, when I returned to the site, it wanted me to login with my email address and password. [inconsistent naming of form fields twixt registration screen and login screen, no doubt].

I couldn't remember which of my half dozen or so email addresses or "+"-added variations of them I'd used, or if I'd used a disposable email like Mailinator to sign up. So I clicked on the "forgot login" link --which then asked enter my account email address, in order to be sent a password reset link!