Sync that has never broken for me and works on a phone. My attempts at keypass with both google drive and syncthing invariably ended up with me needing to periodically do manual reconciliation. I’ve never had this problem with bitwarden. Also, bitwardens passkey hooks work on iOS. They appear unsupported by keepassium.

Probably a bit more polished UX (especially for not too tech-savy people)

but I’d say the biggest difference is integrated multidevice support, either via their cloud or selfhosted…