That's not a great comparison. Basketball is a team sport and there are other categories from which one can assess greatness, such as points, rebounds, assists, triple doubles, etc. Incidentally, it was easier to win an NBA championship in Russell's day. There were only 8 to 9 teams in the whole league for most of his career. (Btw, Rocket Richard has the most hockey championships, but you don't see him even close to being considered the best hockey player of all time).
Golf, being an individual sport, you look at championships, specifically the majors, because those have been around for a long time, whereas other tournaments have come and gone. Jack Nicklaus has the most major championships. Would Tiger have caught him had he not had a catastrophic personal breakdown? Probably, but he couldn't control himself after his father died. Sports are littered with great talents that flamed out short of the pinnacle for many reasons.
Anyway, this is all a subjective discussion with no right or wrong answers. Well, there are some absurd choices that have been thrown up here (some idiot said Evel Knievel!)