Because I want to login to my user account without sending a password over the wire. If telnet can use keypairs to authenticate users then I guess I don't mind that as a solution, but I haven't heard of it? Also I do care about per-user auth because some of us still work in environments where servers have multiple users.

So I don't need root permission or kernel networking stuff setup.

(I do run Wireguard, it just feels like sometimes a VPN is a sledgehammer to solve a port forwarding problem)