Where Moyes falls short is his celebrity status and coolness factor. He can't convince a dressing room full of massive egos and prima donnas who used to be the most popular kids in school that he's the main man they should be looking up to.
Football management isn't like in the video games. It's not simply about having the right brain. It's mostly about projecting the right image. The rest comes down to competent spending and clever coaching - though the big names aren't exactly unique in having that. But even those same big names fail eventually when their squads get tired of old coaching methods and the original charm of the manager's charisma fades (which is exactly what happened to Klopp and Tuchel at Dortmund, Pochettino at Spurs and Mourinho everywhere).
Moyes can go toe to toe with any of them on purely football terms. It's his lack of a 'baller' reputation that precedes him. That's why it's so difficult for a managers to make make it in England unless they've previously made it in another country. It's too competitive in the PL for anybody to build a reputation at the top... without already proving themselves at the top. They're stuck in a catch 22.
If Moyes had done his current job with a German, Dutch, French or Italian team, he would have probably won a few cups or maybe even leagues there. And then if he'd moved to United afterwards, he'd have been much more accepted by the players and fans. Kind of like what happening right now with Ralf Ragnick.