anyone else find these films sad for same reason as me?

I just rewatched the whole saga across 3 days. I love these movies (parts 1 n 2) but always feel sad by the end of them. And I really dont like 3 and i finally figured out that the same reason I hate the third is what I don't like about the first two.

The part that gets me is the falling apart of the corleone family. While I know the mafia is bad, I can't help but love the corleones. They are good people (for most part), and good morals. Family comes first and that's how the don ran it. But even in the first movie we see people die, and close people betray them. That actually is sometimes sadder than dying in that lifestyle.

In part two even more deaths. Mike becomes a monster of a person and nothing like his dad. He kills his brother!! The family went from a big happy family with 5 kids, down to mike Connie and tom. Even their relationships are broken. (I hate how they make it appear as if mike doesn't view tom as a brother).

And part 3, the worst! No tom. No closure on his death either. Just mike and Connie (the fact that Connie becomes mature and part of the family is the only uplifting part) and a whole lot of bad pasts catching up to mike.

Am I the only one that gets sad for these reasons?