The richest guy in the cemetery probably lived a pretty good life.

He could host his friends, people wanted to spend time with him if he wasn't particularly foul.

He could afford better food, better schools, and better medicine. So he was better nourished, better educated, and better taken care of.

He could pursue his interests and support things he cared about, so he felt actualized.

Of course rich people die of cancer or suicide just like the poors. But they do it less and it's more of a tragedy when they do.