I don't know.. I was never really a big fan of any of them maybe save suju for some time in the past, but we got to let them go.

2ne1 is done for. Maybe a reunion concert if they're still up for it and someone is willing to produce that. I'd say they're the group with the best stage presence when they're still active. It's pretty sad that their spiritual successor isn't living to that, Blackpink just don't really have it in them despite having good songs.

Big Bang is still around. They're reported to have a comeback at 2020 and despite the issues surrounding TOP im confident they'll still make a strong comeback in the future.

Girls Generation, they are past their prime and they've got nothing to prove anymore because they've already won it all. Right now I'd say their successor Red Velvet is doing perfectly fine. I'd say focus on them more because they're pretty young with the oldest being the same age as the youngest of Girls Generation.

Suju, I don't know what really happened to them but they have really fallen off. They were like the ones who penetrated the international scene along with Girls Generation. They still release good songs but maybe it's more like there are a lot of new younger boy groups around that are stopping them from rising to the top again. But then Big Bang has been on the scene for god knows how long but they're still on the top. EXO and NCT is doing perfectly fine atm as the next gen for SM's boy groups. I'd still prefer listening to Super Junior's No Other than any of these new songs though. Lol