I can’t say I agree. You claim that Chet lived his life the way he wanted. That sounds like he was in control of his own life while I believe a heroin addict is never in control of his life and could never live the life he wants. Sure he remained successful up till the end of his life but succes doesn’t equal happiness as so many musicians have proved. Chet was a regular visitor of the police station my father in law worked. He was in all sorts of trouble always related to drugs. He got robbed, beaten up and he ended his life by jumping out of a hotel window. That doesn’t sound like a happy person in charge of his own life.
Maybe I shouldn’t have used the term sad person as that has a negative feeling. But he lived a life that could have been so much better and, though he certainly had his moments, I very much doubt if he was really happy.