Try using Roboform! The Roboform firefox extension saves ALL info on the form, not just User and Password.
I have a few Google.com accounts. If I type my username in https://mail.google.com and click the Roboform icon, it knows which password to fill and shows that one on top.
Please try using Roboform for a month and see how Bitwarden could be much better. It can save all fields of the form and later fill them with 1 click, it can detect password fields and offer to save them, etc.