He would have been the 3rd scorer they've needed, he put up career numbers leading into his free agency last season.
Kawhi isn't that good.
Have you seen Parsons this season?
I'm sorry man, he was great in Houston, and looked like he was heading upwards in Dallas when he wasn't injured. But he's washed. He has a flat shot, he's gonna be super-injury prone for the rest of the season, he's not quick enough anymore.
Parsons is done. Had he been who he was in Houston or Dallas when not injured, he would be a great pick-up for kick-starting the Memphis offense and giving them a playmaker. But he's done.
His shot was already super flat before, but his knees being dead means he can't get enough lift to make the shots at all now
Also, Kawhi is a top 6 player already, along with Lebron, Harden, Westbrook, Curry, and Durant. Those six are the ones that, by the strictest definition of super-stars, are definitively super-stars. And Kawhi is only 25. Harden is the next youngest at 27. Kawhi is far closer to AD in age. Kyrie is the same age as him, but he's still not in his prime yet. Kawhi is already a superstar
I'm not sure you've watched that much this year. But Kawhi is deadly in ISO this year, has to produce offensively a bunch for the Spurs, is still the best perimeter defender in the league (especially when he needs to be), has (along with Butler and DeRozan, the other major stars I know that are now doing this) started to draw fouls in a manner similar to Harden, etc. Kawhi is a superstar.
Before, you could argue that he can't just go off, and carry a team on his own. He's done that this year. Maybe he had more help than say, Russ or Harden, but he also has more wins than them.