I personally use Firefox's sync to save passwords across devices, but most passwords I store in a normal lastpass/1password/etc service.

It comes in very handy to have a non-browser-based password store for when you are out and about and dont have access to on of your own laptops/desktops but do have your phone handly (where you can look up the passwords)

Look into Browserpass..

Or Enpass, or if you still want free then Bitwarden.