I'm pretty sure I've seen children get damaged by a couple staying together that shouldn't have as well, so I'd say that's a double-edged sword.
I split up with my ex in 2004 and before we did we went through a lot of counseling. Then I reluctantly agreed to do something else, a
Marriage Builders seminar. I thought it was 100x better than the slow-boat counseling. It didn't save my marriage, but for a while it sure helped. Worth a look-see. I could see it saving a lot of relationships, and I could see doing it before things get too far down the wrong path. Good luck!