Here's what my therapist told me:
When you are a child in an alcoholic family, you have no "out" -- you have no experience of a healthy home, you think dysfunction is "normal," and even if you do realize something is "wrong" you have no choice but to continue living with it. (My oldest was 16 when I left their father; without me knowing it, he had researched getting emancipated because he couldn't stand living in the family.)
If your parents divorce, the non-alcoholic parent, given the proper motivation and help, can be able to provide a healthy home. The alcoholic parent may still be dysfunctional, but the time spent with the "healthy" parent is time when the children can heal and grow.
I want to emphasize that I'm not trying to tell you what to do. But I know that in my mind, I minimized the damage done to the children by my alcoholic marriage. I downplayed it because I didn't really dare to leave. And one of my excuses was that divorce is bad for children.
With the experiences I've had, I would say growing up in an alcoholic family is way worse for children than a divorce is. All my kids are still in counseling to deal with the past, four years after the divorce. They're getting better, but we have seen a lot of regressive behavior when they're trying to "catch up" on a lost childhood.
And to be clear -- their father was not excessively physically abusive to them during our marriage. He only ever hit one of the kids (which I didn't even find out about until a couple of years after the divorce). Therapists say there are "markers" that they may have been sexually abused. That, we haven't dug up yet. But the emotional damage done alone will take them a very long time to work through.
I would weigh very carefully (and realistically) the damage done to the kids by staying vs leaving, if that's your only reason for staying. And I would also work through in therapy whether I was being honest with myself when I said "I'm only staying so that the children don't have to experience a divorce."
And I'm saying that with the greatest of love, caring and gentleness. It's not an easy road regardless of which road you do choose. But I think it's vitally important to be aware of what the consequences are either way.
My friends and family after the divorce told me they were thrilled that I finally left. That they had said for years that the kids and I were in a horrid situation. It took me almost 20 years from the first time I considered leaving till the day I actually left. You can't leave until you're ready. But you're lightyears ahead of where I was because you're asking the question and asking for input. I was just stubbornly holding on to a sinking ship.