Comment by simoncion

I'm not the OP, but I expect VPNs are easier to manage because you don't have to worry about slicing up the very, very limited IPv4 non-public space and puzzling out how to resolve addressing collisions between all of the various networks you have to manage. With IPv6 you can just calculate a /48 ULA prefix and allocate /64s for your VPNs (and every other internal network) out of that. If ever you run out of room, just calculate another /48 and carry on... easy!