Feinstein has Alzheimer's, Fetterman has Brain Damage due to stroke. Both are incapacitated but diagnosis are different.
There are several other male Dems in the Senate and Congress, such as Blumenthal, who are pretty much incapacitated now, and nobody’s clamoring for them to get out.
But one of the things about DiFi (I lived in SF when she was mayor) was that she had a few scraps of common sense. Pelosi, for example, has none.
But I think that’s precisely the reason they suddenly want her out. She’s missed 60 votes (probably Fetterman without his body double and the wonders of video conferencing would have missed a lot of votes as well). She’s easier to get out because she’s a woman, but the reason they really want her gone is that she was only 99.9% reliable. Every so often she’d get away and make an almost sane statement.
Hollyweird can make a body double suit and mask for Fetterman. Probably started years ago. Feinstein not so easy.