>>7027624butterfly is one of my absolute favorite f(x) songs
https://www.youtube.com/watch?v=L2o2MfS2kwQbut yeah, butterflies did sound like an f(x) song. as for why the group died, i never looked too close into it, but i just assumed it was because they were way way less popular than sm expected them to be. snsd dominated the regular pop market and maybe sm intended for f(x) to be competition to 2ne1 and it never panned out. i think they made the music way too good and interesting for sea monkey normies to appreciate so f(x) got blown out of the water by 2ne1/yg. not that there's anything wrong with that, 2ne1 was also a great group.
to be honest, i was really afraid that sm was shoehorning rv into the new f(x) role and getting ready to drop them the second they debuted a new, more normie friendly group. but it's been five albums now and they haven't done it and i really appreciate how good they've been to rv.