why is NCT 4th gen and Blackpink 3rd gen?

nct is 4th gen?

Nobody considers NCT 4th gen.

They are 3rd gen.

4th Gen starts from 2018 onwards. Stray Kids being one of the first groups to debut in 4th Gen.

NCT is multi generational

I consider NCT as 3rd gen.

NCT are not bound by the obscure arbitrary system that's kpop generations

NCT is 3rd gen, only WayV is considered 4th

nct have generations within themselves they are a group that follows the same system as Jpop groups like akb etc... So they can fit any generation

Overall the boygroups "generations" are a bit earlier that the girlgroups. If you look at 2nd gen groups you had TVXQ in 2003 and groups like BigBang and Super Junior that debuted 2005-2006. If you compare to the girlgroups it was 2007 with Girl's Generation, Kara and Wonder Girls. So it's not strange if the boygroups change "generation" a bit earlier than the girlgroups.