TWICE went from having a string of #1 hits to the consecutive flops in a row that we call feel special, more&more, i cant stop me, alcohol free, the feels, scientist, and talk that talk. They went from being called the nations girl group by Onces to fading into obscurity to the Korean GP as a result of their inability to sing live during encores.
2NE1, athough were never called the nations girl group, went from being arguably the second biggest girl group of 2nd gen to becoming known as a group with druggies. Their career never recovered from 2015 and they disbanded quickly after that with a flop song. However, despite all their scandals, 2NE1 has a legacy- something twice does not.