VLC isn't equivalent to Jellyfin or Plex in streaming capabilities, and it's just running on SMB which could be configured with general folder permissions and sharing, allowing access for any media player and not just VLC.

SMB is a share protocol that's pretty standard across ecosystems. I am not sure of your use case and why you are wanting to get rid of Jellyfin but VLC doesn't sound like the tool to do it.

You can configure the folder permissions with a guide here or by searching "Ubuntu smb sharing" or something similar.

SMB is a network protocol developed by Microsoft. It's the protocol used by Windows computers to share files with each other. But the protocol was reverse-engineered and a program called Samba provides SMB functionality on Linux. You only see print$ because your Samba isn't configured with any file shares. You'll have to configure it. You can find guides online about how to configure Samba. Samba also maintains its own user list independent of the system. That's why your local account password didn't work.

Theoretically, you can use SFTP. VLC for Android seems to support it (browse -> add server favorite menu), but in practice I've never been able to connect to my Linux desktop with SFTP from VLC. It's simply not connecting and doesn't produce any error message.