As a service, and as a Firefox extension, this is a gold standard. Bitwarden is actually recommended by cyber experts (myself included)

The functionality just works.

Syncs seemlessly between the Firefox extension, the iOS and Android apps. Autofills with minimum hassle in on all devices. (This is not granted, as there is a famous service in this space that said they do not want to support Firefox and adviced their users to use their service on Chrome.)