[antonvs]

When you have to manage a decent number of users and multiple gateways, you need something to help manage that - whether you write it yourself or use something off the shelf, you can't reasonably just use Wireguard out of the box.

Not to mention that Wireguard is really only one component of what would normally be considered a VPN - the other part is the network routing which depends on netfilter/iptables/ufw etc., which can be quite complex.

I get the impression a lot of people think of "VPN" in terms of their own simple personal connection to some gateway or small set of machines they control, but that's just the most trivial use case.