This is the NBA... one good player can take a team from league-worst to the playoffs in a season.
No way. Good players don’t do that. Heck, even a lot of great players, probably most of them, don’t do that.
What are some of the examples you were thinking of? Russell, Bird, Duncan, KG with some caveats. Those guys are all top-25 all-time. Lebron, Hakeem, MJ, Magic, etc. are all capable. Who else, outside of pantheon players, do you have?
I give Cousins a pass for Sacramento. New Orleans has a bit more of a realistic shot at the playoffs, although their roster and coach are both a mess.