Let's be honest, if Cai Bing looked like Su Riuqi, do you think she would still be on the show and top 7? Not very likely.
She has her own charm and talent, but a significant factor of why she got a lot of votes was due to visual, particularly her eyes. And when she gets the right styling she looks more impressive. Yet in terms of skills, she's still not ready. She still needs more practice, like Yurina. Her personality also doesn't bode well for the group dynamic in the final group. But I believe because of her visual, she might STILL make it on the top 9. And even so, I wouldn't have a problem. However, there are more suitable trainees for the final group compared to her.
And it's not just Cai Bing. There are many many idosl who, honestly speaking, would get very little buzz if they weren't as attractive because their talent/personality wouldn't be able to carry them. But they get hyped up to infinity because of visual + big 3 status.