Yes they do work that much. Do you actually know any executives? My dad is a CFO, and he works at least 80 hours/week. He works from 6am until midnight on weekdays and four-ish hours on Saturday'sand Sunday's. Phone calls at 5am on Sunday's are very normal for him. A day off for him means that he does phone calls and emails at home. Even on vacation he's working at least four hours/day. He's had phone calls on Christmas even. When covid first hit, he was working nonstop seven days/week from 6am-midnight to try to cut the budget without any layoffs. All the executives took 50-60% pay-cuts to save people's jobs.

And that's the same for all the executives at their company including the CEO. Executives at public companies work insanely hard. So Reddit has it wrong.