Because it'll be a while until we'll have another unexpected hit like that. The thing about Rollin' was that the girls were relatively small before this, the fact that it blew up so fast and so quickly was surprising. If we see more unknown songs starting to rise, it takes away the surprise factor, it's not as surprising or exciting to see a song rise slowly anymore(hope that made sense nnn).
Rollin' is a MASSIVE hit that I don't even think Brave Girls will be able to top, so I don't expect the same for every other smaller group. This is a once in a lifetime occurrence.
Y'all calling any song from a small company that rises slowly the 'next Rollin' is just cringe. Everyone said that for Journey to Atlantis but the song went nowhere.