The KeePass ecosystem has gotten a little bit better. It's still not exactly seamless. File sync across all of Windows, Linux, macOS, iOS and Android seems to involve either proprietary user-hostile sync tools or dealing with lots of jank.
As far as I can tell, the only competitor with a similar feature set that even claims to be open-source is Proton Pass. But I can't find any information on whether the server side can be self-hosted.
KeePass as an ecosystem (and possibly other file-based ecosystems) is something I’ve used for around a decade, and while it’s not perfect, I am 100% sure it will be there for me in another decade. I want to own my passwords, and KeePass feels like a safe pair of hands that won’t turn hostile when I’m not looking.
IMO, the secret to keeping the passwords synced with KeePass, is to make sure your client has a direct feature to sync the passwords database to a remote server - SFTP, DAV, SMB, etc. Then all you need to do is to set up a single remote file share to serve that file. Or sync manually, assuming your passwords change slowly - KeePass 2 can sync changes automatically between KDBX files.
While there seems to be an alternative, the root cause of Google's hostility to foss apps does not make me optimistic about this being a stable solution in the long run :(
As far as I can tell, the only competitor with a similar feature set that even claims to be open-source is Proton Pass. But I can't find any information on whether the server side can be self-hosted.