Vance's own experience drives his thinking on that -- remember that his parents divorced. Vance has said (I'm paraphrasing) that divorce may be good for the parents, but it leaves the children unhappy, and for that reason, a woman should abandon her own happiness, stay with her abuser, for the sake of the children. His remark about "shifting spouses like they change underwear" is quite telling about his own bitterness.
Vance made the remarks at an event that took place at Pacifica Christian High School in Southern California. Vance faced backlash after the report came out, but previously said his comments had been misconstrued.
“This is one of the great tricks that I think the sexual revolution pulled on the American populace, which is the idea that like, ‘well, OK, these marriages were fundamentally, you know, they were maybe even violent, but certainly they were unhappy, and so getting rid of them and making it easier for people to shift spouses like they change their underwear, that’s going to make people happier in the long term,'” Vance said, according to the 2022 Vice article.
What he doesn't see to realize -- that somebody like me who lived through it does -- is that abuse of spouse is also very, very bad for children, and is (sadly, but glad I'm gay) passed on to new generations. And forcing couples in such circumstances to stay together is hardly likely to lead to reduce violence and increased harmony!