Right, but that doesn't work when I have a hundred friends, and they each have a hundred friends, and etc.

If I "Share" nodes on my tailnet with a hundred people, it's way closer to what I want.

Tailscale lets you grant various admin roles to other users, but it does also let you share individual nodes to people. Maybe that suits you're needs? It's on you to manage the human trust relationships though, but no technology can fix that problem for you.