Apparently a lot of people are getting Mix Nine and The Unit confused so I’ll try to explain them as best I can.
Mix9 is YG’s survival show where instead of the trainees and idols coming to him, he seeks them out. That’s why in KNK’s statement they said that they were invited and had to think it over, and why there’s so many notable people on it who aren’t really struggling at all. There’s 400 idols/trainees supposedly and they’ll eventually whittle down to a 9 member boy group, and a 9 member girl group who will compete to debut.
The Unit is the “failed” idol reboot show where people had to apply and then audition for a spot on the show. The end result will be a 10 member boy group, and a 10 member girl group. The reason you see members of groups who aren’t doing poorly on there is honestly because of publicity. Between people who want to root for their underrated faves, and the people watching because of the high profile mentors, it’s an easy way to get exposure.
Tbh I think in both cases companies cut a deal so that their idols will get shown and they don’t actually plan for them to end up in the final group. If that happens, fine but it’s not why they’re going on it.