I understand ISPs giving people subnets because there's an expectation that you'll be using a router. Each of your devices will have a public IPv6 address, obvi

I understand ISPs giving people subnets because there's an expectation that you'll be using a router. Each of your devices will have a public IPv6 address, obviating the need for NATs and CGNATs. That's neat, and that enables you to do all sorts of things like reliable p2p communication and servers. But what doesn't make much sense for me is when you're given a subnet many IPv4 address spaces worth addresses on a single network interface on something like a server. Sure you could use that for a VPN, and I did set one up like that, but are there any more use cases? Surely there must be a good explanation why everyone is doing that?