It's cause you want to get to your home boxen from outside.

Surely you know this is a super niche requirement?

You can use IP6 or a commercial rather than domestic ISP if you really need to do it.

It might not be so niche if we weren't all behind NAT firewalls. There would probably be a whole lot more applications that do direct connections between two people, and eliminate the middle-man. There's a reason every major service out there has their applications set up in some cloud to relay the messages back and forth between clients.

There are other solutions to this problem now. Tailscale comes to mind.

That was not the question, it said "people".