A fan-made MV for the latest summer single of SNHG, featuring all those 18 members selected from various SNHG groups to perform the song & compiled from various official footage (the official MV hasn't been released - nor, in fact, produced - yet):
I do know of Utada Hikaru/Amuro Namie because they performed with TLC (especially Hikaru, way back in the day). I'm sure most enthusiasts would know them and Hamasaki Ayumi for their fame. Would have to check out the others though.
Oh, I didn't know that first part...though I feel like I should've. I take it that was part of her appeal? I remember the stupid backlash surrounding Namie in the TLC performance, however. Also knew a couple who were into the BlackPink and [XX##] JPOP group (they're too many to recall besides AKB), but the only one of these I ever remember finding on my own and liking was eNue because of their hood video and TLC influence (loud alarm in the first 3 seconds).
Would the eclipsing be because of the JPOP scandals? Or because the style of JPOP hasn't changed much? I generally prefer JPOP, honestly. That one song I linked above is the only KPOP song I've ever sat through (out of like 20, to be fair). But what I'm really guessing is it has something to do with the "group image" and JPOP having the less en vogue image for today. Like The Rugrats after SpongeBob became the new thing. That's what happened with those RnB-pop crossover groups from the late '90s-early '00s. They were regarded as experimental and not having the idealistic, regional image despite truly taking from the West as far as music was concerned.