Wanna one were so massive in Korea, they dominated all the public attention for boy groups in 2017-2018. At a certain point, they were probably more popular than BTS in Korea.
X1 was on a similar (perhaps slightly smaller) trajectory in 2019, and even with rigging allegations, they broke a few album sales record for rookies (and I think even charted #1 on Melon with their debut song, can’t remember for sure so feel free to correct me)
Between these two groups (and obviously BTS and maybe EXO), there was no time for other boy groups that debuted to establish themselves. Even SVT were pushed aside to a certain extent.
Once they disbanded, interest turned fully to BTS (who arguably transcended the label of just idols by that time) and whatever remained got split between the multiple new and existing groups.
This is why 4th gen bg have lots of fandom power but no solid public recognition and why we’ve only recently been seeing the minor surge in Korean popularity of boy groups (NCT charting on melon, TBZ winning inkigayo)
I think a 4th gen boy group will establish themselves in Korea soon enough, perhaps not to the heights of BTS or Wanna One, but enough to chart well and get invited to popular variety shows.
Lol this is all just my opinion as well, so please don’t come for me.
