That's a good description, yes. The self-hosted aspect is that it makes serving things from home, rather than a VPS, trivial.
For example I replaced Dropbox with an app called Syncthing. Previously to do this I would run Syncthing on a VPS so it was accessible from anywhere, or I would have run it at home but used a VPS with a reverse proxy over OpenVPN back to my house.
With Tailscale running on the Syncthing server at home I have a Tailscale IP address for that, which I use on my laptop to access Syncthing. No need for the VPS (especially important for a high storage requirements app), no complicated VPN setup, reduced attack surface, and the benefit of fast access when I'm at home.