I was led to a tribute video from Sesame Street. He's not dead, but he has retired: the physical work of being Big Bird and Oscar the Grouch has at last just become too much for him.
He muses on his life and fortune, and I'd say they've been good. He was honored to create - in the acting sense, meaning the first to portray and thus to set the standard for these characters, as well as embodying them for ages on film that anyone can watch - two iconic characters whom everybody loves. And, in the process, he has measurably increased the amount of joy and happiness in the world.
I'd call that a good life's work.