The last sentence changes this, you can video chat with people on earth and then invite them to your continent as equals. Could just get your friends and family on with you. Could even find new people online and invite them once you know them.

Plex runs relay servers where your Plex server will connect to the relay and your player will also connect to the relay, making both ends of the connection egress type as far as routing and access control goes. https://support.plex.tv/articles/216766168-accessing-a-server-through-relay/

It’s optional and likely not everyone uses it, but this provides a way for Plex to do remote streaming without the Plex server being reachable directly from the internet.

Separately, it costs money for Plex to run.