I don't think I agree. Coney Barrett is genuinely conservative, but she's more nuanced than her conservative fellows. And she doesn't seem to have any problem disagreeing with them. She's done that several times. I think she may turn out to have much in common with Sandra O'Connor. O'Connor was also conservative, but she often made common cause with RBG, and said she enjoyed finally having a second woman on the bench.
When she graduated from law school near the top of her class, she had job interviews with something like 68 firms. And did not get a single offer, even though she was from a prominent family that was powerful and well-liked in Arizona. She didn't make a huge fuss, but she was very angry. So she went on to set an example.
However, as to the present court.. A lot got lost in the mess surrounding the Kavanaugh nomination. But if it hadn't been for the accusations against him, the question would have been whether he was "too liberal". Some conservatives who followed the DC Circuit Appeals Court, where he was at that time, believed he couldn't be counted on to vote the way Trump would want.