Jews conceive of this world as one with the potential for miracle and wonder, and so the idea of spending time in a fictional world and returning to RL without anyone noticing you'd been gone is a sort of alien one; Why would you want to?

I had never thought of this as a specifically Jewish perspective, but--yes. I have never really understood the appeal of portal fantasies. Or rather, sure, I can see the joy in exploring a strange new world, and if a magic portal opened in my basement that would give me the same novelty as international travel without the inconvenience of airports, I would go through--but it wouldn't be because of dissatisfaction with this world, and if the portal disappeared forever after I had explored a while, I would not then feel cheated out of a lifetime of magic, because this world has a lifetime of magic all on its own.