One of the great mysteries of the Japanese fantasy: why is most of it located in historical fantasy Europe looking place, not historical fantasy Japan? There are, naturally, many such series as well (such as Inuyasha, known by everyone), but they are still a minority. Yet most of the isekai fantasy located in Europe inspired sword and sorcery will have the Japanese MC miss Japanese/East Asian things and work hard to acquire some of them. Instead he/she could have been thrown into historical fantasy Japan and not miss a thing, instead feeling right at home (within reason, it'd still be a fantasy land). There's certainly a weird contradiction here.
In the west most early fantasy settings, the really foundational stuff was heavily based off of European history (The Hobbit, Conan, Elric of Melniboné, etc). Meanwhile in japan, easily one the most influential pieces of fantasy media is Dragon Quest. Dragon Quest uses the european aesthetic (filtered through DBZ) because its biggest influences were early western CRPGs (like Ultima, Wizardry, etc.) which was influenced by D&D and other American tabletop RPGs and those were influenced by The Hobbit, Conan, Elric of Melniboné, you get the point. Like 80-90% of modern japanese fantasy is just copying DQ because it's the safe and the audience is already familiar with it. The rest are just ripping off Berserk, Record of Lodoss War, etc. instead (also heavily influenced by all of the stuff previously mentioned).
There's a small handful of genuinely original stories and settings but those are very few and far between regardless of it's country of origin.
tl:dr all of the most influential fantasy stuff is set in fake europe so they do it too.
I should stop writing rambling posts at 8am. I mean I should stop but I won't.