It's like she's just always there and no one really cares to much if she goes or stays
She's currently on a break. She doesn't need to overexpose herself to stay relevant and instead she spends time with her loved ones and also works on her talents and her artistry.
Can't say the same thing about the latter when it comes to ex-Harmony members unfortunately.
Why is Kesha in the lead? For sure she's irrelevant but definitely not more than Xtina, Madonna, Britney or Mariah who literally nobody talked about since the late 2000s (Xtina even long before that). At least Kesha is fresher in our minds