You can use it for a lot more than just passwords, which IMO is what makes it stand apart from Bitwarden. You can store notes, credit cards, photocopies of IDs, software licenses, key pairs, etc. You get 1GB of storage. They really have turned it into a "vault" for anything digital.
You can store anything you want in it, as long as you are ok with seeing just the first 15 or so characters of the name you give it. Because the column that contains the contents of the vault is thin and non-resizable. Probably because they didn’t have telemetry so they didn’t know.
Fairly sure Bitwarden has done all that for some time. Having had to use both at work, I can't see any killer features that 1Password has in my use case and there are various small things that slow me down when using it.
I've been using Bitwarden for several years and I really like it. However, I do wish it had a few more item "types". Not everything fits into the ["Login", "Card", "Identity", "Secure Note"] array.
1password only has ["Driver Licenses", "Software Licenses", "Documents"] as additional types. "Documents" seems to be doing the heavy lifting, as the others are either a form of "Identity" or "Secure Note".
Bitwarden's support for images attachments is completely useless. You can't view images - the only option is to download them to your Downloads folder, and then you have to remember to delete them and empty your trash.