'A Little Life' by Hanya Yanagihara is a hopeful story
I know thoughts on this book are divided but the main thing I took away from it is hope.
From the start, Jude is presented as a pretty hopeless and depressing character - we learn all of the issues he has early on and his POV is very bleak, not giving a lot of promise to his future. He sees himself as someone not worthy of love or any of the good things that have happened to him.
Still, that doesn't actually stop the good things from happening.
Firstly, Jude gets adopted by Harold. That already is a huge thing. He get a family, something which he had previously thought impossible. Even if he doesn't undestand why Harold would care about him in particular, that doesn't take away from the fact that it did happen.
He is surrounded by people who care about him, who accept his closed off nature. They aren't perfect and they still do hurtful things but that doesn't change that they are still there for him, even if they don't know how to 'fix' him. Jude says it himself that he values his friends. Willem, Malcolm, JB, Andy and many more are consistent parts of the story and they stick by him through a lot of things. The good things they have done matter just as much as the bad ones.
Secondly, he faces his fears. Jude has had many traumatic things happen to him and, as a result, considers things such as relationships as something completely impossible for one like himself. Still, over the course of the story we see him get into relationships. Even if they don't end up well, he still tried. That in itself is incredibly hopeful and impressive. He has tried to have romantic and sexual connections and opened himself up to those possibilities. Even if, in the end, he is happier without sex, he still ends up being happy with Willem and hasn't just given up on it completely after what had happened with Caleb.
Another thing is his legs. From the get go, the situation is described as dire and we pretty much know he will lose the ability to walk one day and things will only get worse. But they don't - in the end, he gets them amputated and is able to walk again. He is able to do things he hasn't before in years. Even though his health is a whole other issue in itself, he pushes through it and by the end is relatively physically healthy (considering everything).
Reading the book, you often get the feeling that things can't get much worse, but you also think that they can't get much better, either. For both, the story proves you wrong. The fact that Jude tries again and again and does things he has given up on is amazing. He has friends, relationships, a family, a career he is good at and plenty of positive experiences. He even opened up to Willem and Harold about his past, and partially to Andy, something which had seemed like yet another impossible feat. But he did it, and that's what matters.
The ending is sad, of course, because Jude does end up killing himself. The important thing is that this doesn't erase the years of trying nor the times that it did actually work out for him and the joy he experienced. Hell, I thought he would die a LOT earlier on than he did. In his own way, he healed from the things he had been put through and, even though it wasn't perfect, it still shows that people can have good things no matter how hopeless they feel.
You can have good experiences and bad experiences. One doesn't cancel out the other and A Little Life is, in my opinion, a great example of that. The tragic ending doesn't erase the positive things that happened to Jude.