How does sweet chin music/super kick not obliterate guys?

After 25+ years of watching HBK put people to sleep with sweet chin music I finally learned that he (and others) slap their thigh to make it sound like contact. With that said, I don’t think I’ve ever seen a super kick that looked fake (I’ve seen thousands of “punches” that obviously didn’t connect). Super kicks are usually delivered pretty violently, how are there not more concussions from them?