At least for fire emblem it was more about practicing basic math operations. You don't really learn anything in Kumon either. You just get better at math through practice.
I think I didn't so much learn new things so much as I got an applied perspective on things that I had already learned. It's one thing to read about value added in a textbook, it's another thing to actually experience it in person buying reagents and selling potions in WoW. You can read about the benefit of fuel transferring lifting stages (aka "asparagus staging") in an article it's another thing to reach that design in KSP, and understand why SpaceX tried to do it.
Yes, that applied perspective is extremely important.
Especially for more abstract topics like, why does a market work better at discovering information than central command-and-control?
A game can't help but have some mechanisms. The mechanisms don't necessarily reflect reality, but they have to bear more weight of themselves than eg just a story does.
Game design shows at least some unintended consequences.
Especially the more simulation type games like Sim City where the game world ticks along without your input, as compared to more heavily scripted player focused games like an FPS.
I think I didn't so much learn new things so much as I got an applied perspective on things that I had already learned. It's one thing to read about value added in a textbook, it's another thing to actually experience it in person buying reagents and selling potions in WoW. You can read about the benefit of fuel transferring lifting stages (aka "asparagus staging") in an article it's another thing to reach that design in KSP, and understand why SpaceX tried to do it.