For noobs who think kpop was born in 2017 I'd like to just take a second to educate you on all the current girl groups f(x) gave birth to.
f(x) was a girl group formed by SM Entertainment in 2009 and they were the originators of teen crush concept.
List of girl groups molded after f(x):
Red Velvet: A much softer version of f(x) with a much softer experimental sound. Recieved a lot of songs that were originally meant for f(x).
Weki Meki: Strong teen crush vibes and weird songs. Sound familiar?
Itzy: The most obvious. Younger 5 member teen crush group to older 9 member nation girl group. Where have I seen that before? Hmm...
Secret Number: Strong f(x) clone with foreign member having insane popularity. Queen Victoria anyone?
StayC: If Chu married NuAbo they would give birth to StayC.
Aespa: f(x) on steroids.
Thats all I got for now.
Hope you learned something today :)