Quantitative ranking of kpop groups tiers. I included most of big 2nd gen to 4th gen groups (the ones who have sold 1+ million, have any KMAs or are in top 20 Korean artists on Spotify).
The ranking is based on equally weighted physicals and digitals (50% Korean, 50% Youtube+Spotify).
Tiers are based on clustering of final ranking index.
Some of the individual inputs, including extras (critical acclaim, US success):
BTS is most successful based on any metric, except Korean digitals where BigBang is leading with a big margin (half of these points from pre-Gaon era).
In everything else noone comes even close to BTS.
Theres a cluster of big3 girl groups whose nbr of KMA nominations exceeds the success level and there seems to be some trend for KMA nominations being at least a tiny bit correlated to success for others. BTS is clearly separated from the rest of kpop.
Physical sales: Gaon + Oricon
Korean Digitals: Gaon end of year chart + Melon end of year charts for pre 2010 (100 points for #1, 1 point for #100)
Spotify: total streams
YT: total streams
Hot100 & BB200: full history (Hot 100: 100 points for #1, 1 point for #100, BB200: (200 points for #1, 1 point for #200))