A local password manager becomes a "cloud" one trivially if you just stick the database file on a synced drive. You don't have to trust the drive's host at all

A local password manager becomes a "cloud" one trivially if you just stick the database file on a synced drive. You don't have to trust the drive's host at all since it's just an encrypted blob. KeePass makes this easy, at least in theory, though I was never happy with the phone app.