Most things people self host are either torrent clients, HTTP(s) or are game servers. The first one can pick a port arbitrarily. The second can do host routing. The third - some of them support SRV records so you can direct the client to an arbitrary port. It’s becoming less common to need multiple public IPv4 addresses.

I can deal with that even. I drew the line, though, when the spider that was hanging out on the ceiling above the shower for a week decided it was time to descend and introduce itself in the middle of my shower.