Why depend on Tailscale when you can go 100% open source and use slack's nebula or plain old wireguard or one of those open source wireguard manager apps.
Because the whole point of Tailscale is that it's zero config, I don't really want ot mess about with wireguard.
Former Wireguard user here. It's fantastic for point to point VPN but I moved to Tailscale last week and it's so much better having all of my devices on one flat network. Not to mention getting my parents devices on there with no config.
Now image having twenty employees running Wireguard. Having to send them keys and configs, off boarding and managing it.
Tailscale (or Headscale for that matter if you host it yourself) is magical in comparison.