That is an interesting thought. If humans were immortal, would we have any government?..hm, yeah, I believe we still would. I think it’s less about the threat of death for an individual and more about the management of resources for a population.
But the intent would not be to see what works in a video game and try to use it IRL, the intention is to see where these systems breakdown in unforeseen ways when implemented at scale.
But mostly, I just want to see new fun ideas in the genre. There are no new MMOs willing to take the risk of letting one player’s experience be dependent on the behaviour of another player, let alone allow a fully player-managed government. For now we live in a world where Destiny 2 is what qualifies as an MMO. But I digress.