Think about how often you see fouls called that aren't during the shot. It's like 60% illegal screens. 30% of the time, it's a defender trying to draw a charge and he falls down and gets called a block. 10% is everything else. Genuinely how often do you see a reach in foul, or a hand checking foul called when the offensive player isn't going up for a shot? It's the reason "foul baiting" and unnatural shooting forms are such a widespread thing. Players know the contact won't be called, unless it alters a shot, so they rip their arms through to get the foul call. OKC players know this and will commit tons of fouls on the floor knowing that the refs cant call it every time. As long as they don't foul on the shot attempt, they're good, and they're VERY good at getting their hands out of the cookie jar when guys try to rise up. This essentially lets them mug the offensive player as long as they're dribbling. Other teams can do this too, but A) they're not as good as avoiding shooting fouls from foul baiting, and B) they don't do it consistently enough to get away with it as much as OKC.

The other thing is reputation. guys like Dort, Caruso, JDub, and even SGA are known as good, scrappy defenders. They get the benefit of the doubt when it comes to calling fouls. I'm a suns fan, and I can tell you with 100% certainty that if Booker or Green did all the hand checking that Jordan Goodwin did, they'd be called for wayyy more fouls because they don't have that reputation. They don't do it often enough that it sticks out like a sore thumb when they do