Should I intervene in this conflict between my uncle and his family?

I (late 20s, F) would like some outside perspective on a family situation that has been going on for years. For context: My uncle "Victor" (late 50M) and my aunt "Alice" (late 40F) have been together for over 20 years. They have one daughter, "Samanta" (20F), who is my cousin. I don't live with them, but I see them regularly. My uncle is close to my mother (his sister) and often talks to us about what's going on at home, so while I'm obviously not there to witness everything, I've seen this family dynamic develop over many years. At the beginning of their relationship, my uncle emigrated to another country first, and about a year later my aunt joined him. During that year, she cheated on him. He found out, but they stayed together. Not long after, she became pregnant with my cousin. Obviously, having a child didn't erase what had happened, and from what I've seen over the years, their relationship has slowly deteriorated. My uncle has a bad temper. He raises his voice very quickly when he's frustrated. However, he's also an incredibly generous person who is always willing to help family or friends whenever they need it. My aunt is very manipulative. She always seems to think she's the smartest person in the room and that everyone else is an idiot. She also has a habit of keeping information to herself and making decisions without telling anyone. Growing up, she also did everything she could to distance my cousin from me and my mother (my uncle's sister). I remember long periods during my childhood when my uncle and my mother didn't speak because of family drama. I tried several times over the years to build a relationship with my cousin by inviting her to do things together, but there was always an excuse. My aunt also read all of my cousin's messages, even when she was older. Financially, my uncle has always been the main provider. As far as I know, he paid for almost everything in the household. My aunt worked, but her money was always "her money" and didn't really contribute much to the household expenses. Fast forward to today. My uncle and aunt have been sleeping in separate bedrooms for years. My cousin also seems to dislike my uncle more and more every year, and I honestly think she's been heavily influenced by my aunt. She comes across as very entitled and almost always takes her mother's side. Recently, my uncle asked for them to have separate bank accounts because he felt that every euro he put into their joint account simply disappeared. I don't know exactly how much my aunt contributes financially, but I don't think it's much. He also asked her to start contributing to the mortgage. Around the same time, she inherited a house from her mother in their home country. She never told him what happened to it. She may have sold it, she may not have—we genuinely don't know. After that conversation, my aunt and cousin stopped speaking to my uncle altogether. They also stopped eating the food he buys for the household. The latest incident happened one morning. My uncle and my cousin were both in the kitchen having breakfast. As he was leaving, he tapped on the table with his hand, almost like someone knocking on a door to get someone's attention. My cousin immediately started shouting at him through clenched teeth. While she was yelling, she kept glancing over at my aunt, who was standing in the doorway with what I can only describe as a smug expression. Since then, my aunt and cousin have continued refusing to speak to him. My uncle seems to avoid being at home as much as possible, preferring to stay at work or find something else to do because the atmosphere in the house is incredibly tense. Honestly, I don't understand why they're still together. In my opinion, they should have divorced years ago. I think my uncle stayed because he wanted to give my cousin a "normal" family, but I honestly believe everyone would have been better off if they had separated when she was young and shared custody. The only practical issue is that if they sold the apartment, neither of them would probably be able to afford another home in the same area. I also don't know whether it's worth trying to have a relationship with my cousin anymore. I've tried many times over the years, but it's always been one-sided. I feel sorry for my uncle. Despite his temper, I genuinely think he has sacrificed a lot of his own happiness over the years for the sake of keeping the family together. At the same time, I know I'm only seeing things from the outside, and every story has two sides. Am I looking at this situation the wrong way? Is there something I'm missing? And is there any point in trying to stay involved, or is this one of those situations where I just have to accept that I can't fix a family dynamic that's been broken for decades?