There's still a big difference between a system service binding to the port vs a random app binding to it. Even on a phone (that's not a "server" in the tradit

There's still a big difference between a system service binding to the port vs a random app binding to it. Even on a phone (that's not a "server" in the traditional sense), e.g. listening on UDP port 5353 is needed to show up in mDNS.