This is an empirical question. 10 seconds of googling suggests CEOs work about 60 hours/week average: https://www.cnbc.com/2018/06/20/harvard-study-what-ceos-do-a... so harder than the average employee, but I'm not sure by what measure anyone believes they work 100x harder.

Perhaps the difference between a good CEO and a bad CEO is 100-1000000x the average worker's productivity, or even more. I suspect the real disagreement is: does that justify paying a CEO 10-100000x more than the average worker, even if they only work 1.5x as hard? From the perspective of a company it may be worthwhile, but I can see how some people might feel that's a little unfair.