Comment by rainsford

It's not really "basically wireguard" and you don't have to pay for it for personal use. Wireguard is indeed pretty easy to set up, but basic Wireguard doesn't get you the two most significant features of Tailscale, mesh connections and access controls.

Tailscale does use Wireguard, but it establishes connections between each of your devices, in many cases these will be direct connections even if the devices in question are behind NAT or firewalls. Not every use-case benefits from this over a more traditional hub and spoke VPN model, but for those that do, it would be much more complicated to roll your own version of this. The built-in access controls are also something you could roll your own version of on top of Wireguard, but certainly not as easily as Tailscale makes it.

There's also a third major "feature" that is really just an amalgamation of everything Tailscale builds in and how it's intended to be used, which is that your network works and looks the same even as devices move around if you fully set up your environment to be Tailscale based. Again not everyone needs this, but it can be useful for those that do, and it's not something you get from vanilla Wireguard without additional effort.