One point is that while memorizing specific causes of the fall of the roman empire may not be especially useful, acquiring the self-discipline necessary to do this without a game to motivate you might be very useful.

A big part of education today is memorization. Perhaps it is wrong, but it is going to stay here for a while anyway. And at least partially it is necessary; how else would one learn e.g. a vocabulary of a foreign language? So while it is great to invent games that teach principles instead of memorization, let's not forget that there is a ton of low-hanging fruit in making the memorization more pleasant. If we could just take all the memorization of elementary and high school, and turn it into one big cool game, it would probably make the world a much better place. How much resources (especially human resources) do we spend today on forcing the kids to learn things they try to avoid learning? Instead we could just give them a computer game, and leave teachers only with the task of explaining things. Everyone could get today's high school level education without most of the frustration. Recently I started using Anki for memorization, and it seems to work great. But I still need some minimum willpower to start it every day. For me that is easy, because with my small amounts of data, I get usually 10-20 questions a day. But if I tried to use it in real time for high-school knowledge, that would be much more. Also, today I know exactly why I am learning, but for a small child it is an externally imposed duty, with uncertain rewards in a very far future. So some additional rewards would be nice. It could be interesting to make a school where in the morning the students would play some gamified Anki system, and in the afternoon they would work in groups or discuss topics with teachers.