I've noticed this recently after watching clips from KCON, and some other festivals which were organized in Europe & US
honestly it seems like people who attend those festivals outside of Korea seem to be very happy about it and they are having fun and chanting and jumping and screaming to all groups, it doesn't even matter if those groups are popular
meanwhile in Korea sometimes people either stand like manequines or act like rocks when some lesser known group appears on stage
duh, even with mid-tier groups appear sometimes you will see one sector of fans of that group vibing and being happy, and other ones being frozen...
