There is no simple answer to that question. Country star Loretta Lynn married in her young teens and stayed with him until he died, despite the fact that he was a boozer who slapped and cheated on her. She has been quoted as saying, "He never hit me one time, that I didn't hit him back twice." (Please don't anybody take that as advocating violence. She's making light of having to defend herself physically, and please understand that she is a tiny lady.) I believe this did ease up as the years went by. It was the same for a lot of my family, who are from the same part of Appalachia. One example is my great-uncle, who in his younger years was quite an unsavory person. But the 15-year-old that he married when he was 30 stayed with him until his death as an old man as well. She will tell anyone who asks that the first 25 or 30 years of their marriage was horrible, but the last 10 were wonderful.
I am not going to tell anyone whose life is in danger, or who fears for the safety of the children, that they absolutely must stay with the abusive spouse. And I also point out that leaving for your own safety or that of the children is not the same as divorce. You can get out, be safe, and still be married on paper, and stay celibate if you don't believe in divorce.
Which leads me to my own experience. And that, I will springboard into another thread because this post got too long before I edited that out.