I feel like articles like this do Tailscale a disservice to a certain degree. Most people know Tailscale helps with managing the mesh of connected devices. And as many people have said here you can do this manually with Wireguard, Netbird, Nebula, ZeroTier and many others. Why Tailscale is so helpful is the ACL system. I have about 40 devices connected to my Tailnet and depending on tags devices can or can't access direct communication and also certain exit node networks. Traditional VPNs generally suck because you dump out of a host and have flat access to everything. Tailscale allows you to segment access without disrupting general Internet access with minimal friction and ACLs allow segmentation to happen at the user / device level. Most people aren't using Tailscale ACLs, in fact I rarely hear it discussed. Also the article fails to mention Tailscale Peer Relays [0] which decreases the dependency on DERP relays significantly and are controlled by, you guessed it, ACLs.

[0] https://tailscale.com/blog/peer-relays-beta