That STV episode was an allegory about dealing with garbage. The trash haulers thought they were dumping their toxic waste into an uninhabited void, but it turned out the void was inhabited and the waste was poisoning the inhabitants. That is somewhat analogous to dumping trash or raw sewage into the oceans. When we began doing that we thought the oceans were really really really big. Now we're finding out they aren't infinitely big. Space really is infinitely big, but someday we might also find out that isn't the case.