If Plex is "just file sharing" then I guarantee you'd find Tailscale "just WireGuard".

I enjoy that relative "normies" can depend on it/integrate it without me having to go through annoying bits. I like that it "just works" without requiring loads of annoying networking.

For example, my aging mother just got a replacement computer and I am able to make it easy to access and remotely administer by just putting Tailscale on it, and have that work seamlessly with my other devices and connections. If one day I want to fully self-host, then I can run Headscale.