Blackpink were still the top GG in 2022 and had successful solos the year before, RV released Feel My Rhythm which was the biggest 3rd gen song that year in Korea, Nayeon had a successful solo, Mamamoo did a world tour.
4th gen succeeded because they made good music and had distinct identities. Not because 3rd gen declined.
I think it’s because top 4th-gen groups were actually unique when they started taking over. Aespa had the futuristic concept, Ive came in with the modern elegant princess vibe, and Nj literally changed Kpop landscape after Bp’s wave a few years earlier. None of them reheating 3rd gen nachos so they all can coexist peacefully, especially with Bp popularity.
With 5th-gen groups now, it feels like they’re either rehashing Nj’s style or Bp’s. ADP being the “unique” one is kind of proof of that.