Just write simple script. Why this service is needed. Provisioning VPN server is not a rocket science.
And maybe a smaller set like me who are geeks but prefer not to manage their own server even from a script. As if using such a script means no problems and you wont be googling for why x y or z isn’t working.
Some of just don't like screwing with servers and are willing to pay a premium for that. I absolutly loathe managing servers.