Right -- Durant was essentially where DeMarcus Cousins was a couple years ago (and arguably still is).
I think Durant has more than proved that he's a great, winning player at this point. No, he hasn't won the title yet, but I think any team of decent players with Durant on it would win a lot of games. He's probably going to win the MVP this season, and unlike Derrick Rose a few years back, he 100% deserves it.
Cousins is in the same boat as Kevin Love -- statistically dominant. Is probably gonna be a 20/10 guy for years to come, barring major injuries. But he's yet to show he can be the main guy on a good team.