tbh people are too stupid to realize that players still handcheck a ton, and that guys like harden, kd, kawhi, kobe, steph, dame and many others have simply figured out that you can make handchecking a worthless and even bad defensive move by either doing the swingthrough, or by grabbing/hooking the hand check in a way that the ref is forced to call a legal (albeit cheap) foul. and even if the ref doesn't call a foul, by doing the hook/grab, it throws the defenders balance and position off, and pretty much puts them at the offensive players mercy
and tbh its not his fault, nor the refs fault. it was just bound to happen in time that players find loopholes in the rules, just the same way 80s/90s players made flopping become a common strategy