Outline is part of Jigsaw, which is a part of Google. Is it truly private?[0][1]
[0]: https://getoutline.org/faq/ under the "Outline Brand" section
[1]: https://github.com/Jigsaw-Code/?q=outline Jigsaw's Github with the Google affiliation.
Tailscale is cool for sure but it also requires a third party involved in this. Outline has no third party server component. For almost everyone Outline is much easier to setup and use.
> so no sharing if config or keys. just invite them to your tailnet of share the server to their tailnet.
It's the same level of effort as outline. Outline manager has a button that generates an invite that someone else just puts into the outline client and now they have access to your VPN. You can revoke keys and do all the things you'd expect to be able to do, but again with no third party involved.