Giannis is clearly the best defensive superstar-level player in the league. It’s not that close.
Add to that that he is a top five scorer and I am think it’s fair to put him at the top.
That has been true for a while now, but if there are 6 minutes to go in the 4th quarter of a finals, he just isn't the best player in the world for that. Durant is #1. Several other players are more likely to come through too.
There is more to basketball than just shooting though. Giannis dominated the last few minutes last night. He made several massive defensive plays (not just the block, but others), he made quite a few clutch passes, he got key rebounds, etc. His last points were at 3:40 to pull the Bucks to within 1, but he was all over the place doing everything after that. The Bucks don't win without Giannis even though he didn't score a single point down the stretch. Some games though, he is a scoring machine down the stretch, dominating in the paint, getting opponents into foul trouble, and scoring at an insane rate in the paint. In game 3, Giannis scored 41 points with an average shot distance of 2'. He just can't be stopped in the paint because he is such a skilled athlete. He doesn't just overwhelm people like Shaq did, but you still can't stop him from doing whatever he wants and if you by chance do get position on him, he is a good passer with good instincts (like passing it to Connaughton to hit that critical 3 down the stretch).
If I need 3 points with 10 seconds left, I'm not taking Giannis because he obviously isn't a great 3 point shooter, but down 1 or 2, I want Giannis because I know Giannis isn't going to be denied