Why did Fury/AJ not use the Chisora approach?

Fury clearly won 4-7 and 12... I'd give Fury 5.

 

I forget what round it was in but when Fury went to clinch Usyk, Usyk blew it up IMMEDIATELY. I'm not exaggerating when I say it was best, fastest, most efficient clinch counter I'd ever seen in my life. He broke it up and I think even managed to manoeuvre to Fury's back in an instant. I literally said out loud "You know he's been practicing that in drills". His reflexes, position and footwork are so good that as you already mentioned, it doesn't go how you'd expect it to. It's not that AJ and Fury didn't try it, it's just harder to sustain than people think.

Like body punching. Fury was very successfully throwing body punches, until he wasn't. No failure on his part, just adaptive success on Usyk's.

 

I had Fury winning 6 and 7.

I don't count pulling silly faces and playing to the crowd when getting punch in the face as point scoring.

Usyk controlled the ring, had Fury backing up all night, piled o. the pressure, controlled the distance well, landed the more cleaner shots and dominated the fight. Plus the standing count when Fury was dead on his feet.

 

This is why Usyk came out unexpectedly aggressive against AJ in the first fight. He nailed AJ with a few straight lefts right down the pipe that he loaded up on early. That was a great game plan to deter AJ from coming forward on to more damage from Usyk. AJ resorted to fighting flat footed for big chunks of the fight which allowed Usyk to circle and pot shot him all night.