William Wordsworth is appropriate here: “The good die first, and they whose hearts are dry as summer dust burn to the socket.”
I have a theory why the evil live so long.
The good have already completed their task on Earth, and God wants them near (especially before they screw up). On the other hand, God lets the evil live on, so they have every opportunity to redeem themselves.
Mugabe should live to about 975 years old.
The short stories of Flannery O'Connor illustrate that theme, if occasionally, quite violently.