Let’s list people who, in any field, made a big impact or had big success, and then either quit or died relatively soon after as a (relatively) young man or woman. How young is young is up to you. People who suddenly became bad, but didn’t quit or die, don’t count. Athletes can count if they died or retired even younger than one naturally expects an athlete to retire.
If someone seems like a borderline case, just include them but explain what makes them one.
I don’t know if Rick Moranis counts as “making a big splash”, but he quit his acting career when his wife died of cancer, because he felt it was more important for his kids to have a full-time parent, which I think was a gutsy decision.
J. D. Salinger who wrote Catcher in the Rye in 1951 had his last work published in 1965 and then lived a rather reclusive life for 45 years until his death.
Gary Larson, creator of The Far Side. He wasn’t that “young” at 45, but he did quit while his comic was still very popular; IIRC, he mentioned that he didn’t want to end up one of those comic artists who keeps going until they burn out & bury their original reputation & work under garbage.
Michael Jordan - First retired from basketball at a fairly young age, though he came back and re-retired a few more times. James K. Polk - Only served one term as president and didn’t run for re-election, having accomplished everything he’d wanted (my cite is the TMBG song).