If 4th generation started in 2018 with the debut of Stray Kids And (G)idle it means It has been 3 years into the new generation of kpop (2018-2021)
For 3rd generation it started in 2012 with the debut of EXO, BTOB and BAP so 3 years it would be 2015 (2012-2015).
I just want to see how different the 2015 list is compare to the current top 3rd gen groups and how 4th gen can easily have that same twist.