- why play a game when you could work for society?
- why work for society when you could create replicateable value for society's future?
- why do that when you could change society?
- why do that when you could save lives today?
- why do that when you could save humanity from extinction?
- why do that, any of that...at all?
At the end of the day, the only remotely satisfactory reason for doing anything is to pursue individual fulfillment (even if that be in pursuit of a collective goal).
Additionally, progress in any valuable-to-society pursuit does not happen singularly within the confines of an academic or professional field. Human brains work in mysterious ways, and giving them a wider space of things to bounce off of and different systems to analyze only strengthens it, not take away from it.
I would be willing to bet the time (if/when) we find a cure to cancer will be concurrent with the most board-game-shaped-activities being participated in by humanity, not the least.
TL;DR: human brain utility is non-zero-sum, unlike computers.