I want my parents to get divorced (Long post; TW Domestic violence)

Or rather, I want my mother to be happy. They have been together for over 30 years, but I never needed FDS to recognize that their relationship is beyond toxic. As a child, I witnessed on many occasions my father drinking too much and being verbally and physically abusive to my mother. He was always an asshole to me and I resented him so much growing up. I begged my mother to leave him when I was just in 3rd grade, but she never would. She got married the first time when she was 19 and it took her ex-husband trying to strangle her for her to wake up and leave (she would have died had her neighbors not knocked on the door--a miracle of God). She then married my dad just a few years later, and while I cannot say for sure that he has never tried to kill her, he still is abusive in many ways--The biggest examples being he has always been super controlling and does not allow my mother to go anywhere (besides work) without him, and he frequently has emotional outbursts and yells at her for minor things (my mom thinks he is bipolar). When I was a teenager, my mother discovered the internet and social media, and has since then been addicted (to both alcohol and social media) to the point where I feel like I don't actually have a mother. She is rarely sober. She is just a shell of a person living in a fantasyland with all her internet friends, many of which are random men who give her attention she never receives from my father. This led to my father finding nude pics my mother would send to these strangers, and inevitably, a lot of additional turmoil in their marriage. I want to spare the details but feel these points are necessary to the current situation I am stuck between.

I am an adult now, and can more clearly see the bigger picture. My parents are empty-nesters and no longer have either of their parents. I think this has changed them in both good and bad ways. Both of them seem to be coming to terms with their lives and mortality, which means my dad has seemingly been trying to repair his relationship with me, and we are on okay terms. He confides in me about how unsatisfied he is in his marriage because of my mother's addictions. I genuinely can sympathize with how unhappy he is with my mother because my mother hasn't been 'present' in decades now. But, I know the damage has been done and I'm not advocating for him to be let off the hook for his behavior. My mother, on the other hand, is just so defeated and depressed all the time. She hates her life. My father has managed to isolate her from the rest of her family so she has no one but me, and I live far away and just keep in very limited contact with them. I have tried going full no-contact, but I worry too much about my mother. I know she is an adult and can make her own choices, but she has never learned how to live on her own. She has never made her own choices because the men she chose would never allow for it. I am writing this because I am currently visiting them for the holidays and the energy has just been so depressing. I want to help my mother leave but I don't think she ever will. At minimum, I want her to be able to have at least some fulfillment in life by getting to spend time with her other family members without fear of my father punishing her for it. I want to reach out to other family members and ask for their help, but I don't know if that is a good idea. I don't want to put my mother in a worse situation. I feel tremendous guilt seemingly being caught between my parents' happiness, but I don't know if there is anything I can or should do. Any advice is appreciated.