I think you can make a case that Kawhi is better, but overall, I don't think so.
I wouldn't even put him top 10.
7. Jimmy Butler
Kawhi is the best player in the world he proved that last year he played Giannis one on one in the post season and out played him hands down plus Kawhi has a jumper like no other defense like no other and an ability to pretty much posterize everyone and anyone.
Joel had a 0 point game against Toronto he is bad
Giannis is the most dominant player in the NBA. Kawhi is dominant on occasion, but between inconsistent play and taking nights off, Freak is consistently the better player. And when they played earlier this year, Kawhi chose to take a night off vs. face Freak.
As far as that series, IMO, it's not that Kawhi significantly outplayed him as much as it was that Kawhi had the better supporting cast. Still does, IMO. I still think LAC is the favorite to win it all, no matter MIL's record.
I normally hate these sort of arguments because often between great players one gets into nuance and flavor. Chocolate vs vanilla? What is more important to you? Length vs speed? Hops vs strength? Rebounding vs scoring?
My own personally biases give the edge to Kawhi, because when healthy I see him as just so much more versatile, able to affect more of the game. Both players can score from 3 levels, but Kawhi is way more dangerous from outside. And he is more varied in the way he attacks a defense with the ball in his hands. And defensively, Kawhi routinely takes his man out of the offense.
Even in the red-hot game Tatum had the other day, it was mostly against other players. Even though he was indeed mostly guarded by Kawhi in that game (a massive 33 possessions) Tatum actually only took 3 of his shots while guarded by Kawhi. Kawhi either denied him the ball or wouldn't give him a good look at the hoop. All three of those shots were threes. And that was in a game when Tatum just lit up other Clippers who guarded him. He scored 20+ of his points against Lou, Landry & Harrel in less than 15 possessions.
Many fans look at that game as demonstrating Tatum's emergence as a super-star. But when you look under the hood, that game also showed just how impressive Kawhi is as a defender.
But I also get a lot of the reasons why some would pick Giannis. He's not the outside threat that Kawhi is, but he's so ridiculously hard to stop going downhill to the hoop. And he's getting better and better as a passer. And defensively, while he's not as versatile (Kawhi can guard fast quick guards that Giannis can't) he does have greater length which matters when you are closer to the hoop. Kawhi is incredibly strong and can defend even the best big men at an extremely high level. But that extra bit of length does matter and so I give an edge to GA when defending in the paint.
Both are pretty amazing. But I'll give the edge to Kawhi for the reasons I stated. Plus, so far, he has a far more impressive resume' of achievements.