Dfiction, moon viewing festivals are a huge part of East Asian culture. Each one has their own way of celebrating it, as it’s generally associated with harvest festivals as well. Chinese culture, for example, has the Mid-Autumn festival, when pretty much any Chinese family will have mooncakes in their home - an indispensable treat for this time. Admittedly, though, to those not part of a related ethnic group it may be no more than trivia - but I definitely wouldn’t consider something cultural to be useless knowledge. It’s always interesting to broaden your horizons and learn more about the world! I wouldn’t consider knowing about Thanksgiving useless, no?
Also, Fuwasagi, it’s more like the Lunarians from Touhou are based on this myth lul