Man I wish not being a CEO was as easy as being one. Hell, you can be CEO of like 6 different companies, have a football team plus of kids and still have time to shitpost on Twitter all day long, grind vidya and generally doss off.
A CEO of multiple large corporations and I guess a political actor now with 12(!) children beats all the young folks with unlimited time to sink into that game.
No way in hell he does not pay somewhere or someone to get to that level.
Musk is no superhuman. He might brag about this with Rogan but to me this fact more than any other shows how delusional and unlikable he is nowadays.
The best heuristics are those the candidate will never prepare or even think about. I don't think it's difficult to find one. What happens though is when it becomes popular and everyone starts doing it, then everyone starts preparing for it and then looses most of it's predictive ability.
Filtering in a sense is an arms race between finding new novel heuristics and ambitious careerists seeking to game those very heuristics. In the past it was the college degree, then extracurriculars, then leetcode, might even be these games in the future.
"Good at hard video games" may tell you something about a candidate, but it also introduces bias against people who don't play video games.
I had a boss once, really into competitive sports, who would say that he wouldn't hire anyone who hadn't competed in some sport in school. He would not have counted video games or e-sports -- he meant basketball, football, hockey, soccer, etc. He thought playing team sports meant a person had both cooperative and competitive natures. He ended up with a few jock sycophants.
Besides the obvious personal bias based on shared interests, claiming something gives a strong hire signal without data to back that up doesn't mean anything. If you only hire people good at hard video games you don't know how many equally good hires you passed on because they don't play video games. Selection bias will confirm what you already believe, but you can't come to any general conclusion that video game performance correlates to or predicts job performance.
In Musk's case I doubt you'd find him a strong hire. What company would want a person with such obvious narcissistic tendencies? An employee who calls someone "paedo guy" online, verbally abuses other employees, lies, exaggerates, makes repeated crazy predictions, and acts on a whim? Would your company want a person who brought a flurry of lawsuits with them? Even if you admire Elon Musk I think anyone who has had to work with such personalities would call him a terrible hire, good at Diablo 4 or not.