what I mean is in West and even japanese music industry you see artists of all ages (young idols/boyband , old boyband, soloist) and they have fans , I'm especially talking about older artist in West we see over 40s artist that perform and tour and same apply to some japanese solo artist/bg/band. However, we don't see this in kpop , first we rarely see a successful old korean solo artist and most idols are either only active in the entreatment industry or sometimes release a solo but don't do concerts in korea and we don't see them a lot in end of the year show or as special guest in music show.
Plus I noticed the fan age, in japan & west bg, gg and solo have older/young fans unlike korean with kpop. The way west and japan treat music is completely different than korea, also there are different popular artist with different music genres in the west (pop, R&B, rock, hiphop) and in japan there are a lot of genres too.