Considering that currently for most Westerners "Asian music = k-pop", do you think that Japanese music is the "great hidden treasure" for us Westerners? I mean, the Japanese music industry besides being The largest in Asia, it is also the most diverse, you have idols, you have heavy metal, you have dozens of rock sub-genres, you have folk, you have j-electro, j-rap, many different genres of pop. With this I am not saying that Korea does not have these genres, but come on, in Korea a rock band will never fill a stadium.
Also let's be honest, although it is true that thanks to acts like bts or bp, k-pop has gained a lot of fame in the west, it is still relatively generic music, come on, 80% of the Korean music industry are idols, and the other 20 % is relatively boring music for a Westerner.
Therefore fans of rock, electronica, etc. will never approach other Asian musics because they will come with the prejudice that it could be the same as k-pop
I think that the day that Westerners are really interested in Japanese music, their heads will explode, and it is that Japan, unlike Korea, has a niche for everyone, idols, metal, rap, pop, etc etc etc