I thought this about Sotomayor until very recently, but I've come to believe she's correct in staying: I think she's responsible for the slow and hesitant but steady signs that Barrett is beginning to poke a few toes out of Batshitville.
It's not happening incredibly *quickly*, and Barrett is still doing a bunch of damage along the way, but she *has* made some movement in even the short time she's been on the Court so far. And I think Sotomayor is working on getting her to pull a Souter.
Barrett outright stating that the dissent has it correct with respect to admissibility of evidence in the immunity case is not nothing. There is a very real chance to get to Barrett on issues like the death penalty, and it also helps that her male colleagues suck and talk over her.