KeepassXC can sync changes between your opened database and the (modified) file on your storage. However, you need to make sure your sync tool doesn’t see conflicts and renames the file, i.e. don’t save the database on multiple systems at nearly the same time.
Oh that is nice, but NextCloud never made effective use of that. It's been a while but I also found the browser plugins and methods to use the DB on mobile platforms cumbersome. Idk, perhaps much has changed, I have been on Vaultwarden for years now, and more recently switched to Proton Pass. Both have excellent Web UIs, iOS/Android apps and browser plugins.
Moreover, Vaultwarden and Proton Pass make using Passkeys and sharing credentials with org or family members trivial (arguably Proton Pass even more so than Vaultwarden).
