I feel like there are always a few groups from each era where multiple members in the same group are more popular as actors or soloists etc than the group is.
To be honest with some of Kpop groups I really feel like group activities and promotions hender the careers of the group members and they are just doing this stuff because they have to until the contract ends.
So, I don't piss off any fans, I'll use an inactive group as an example. Groups like Ze:A where like half of the members became hugely generally public popular in Korea after they stopped focusing on the group activities. Park Hyungsik, Siwan, and Kwanghee being the biggest from that group. I feel like the industry takes you more seriously when you're not labeled an Idol Actor and you don't have a ton of group schedules to do etc.
I know I'm not the only one that notices stuff like this, I'm kind of scared to mention it though as a lot of hardcore fans in fandoms worship the group even if it can be at the expense of the members in the group.