I created my account many years ago with an email from Hotmail at the time. The email is no longer valid because is compromised but there isn't a way to update or remove that association from my yahoo account. In the recover section, I get the message This is your Yahoo account username, so it can't be removed.

So there should be an option to delete or at least another way to sing in without sending a link to that email because anyone with access to that email can access my yahoo account.