Don’t buy the hustle porn. Most people in these roles are leisure class and working essentially part time jobs. Their most important functions are PR and sales, which in this age aren’t nothing for sure — that’s just not enough work to really take your whole day. It’s why seeing people be CEO of multiple companies actually isn’t rare and how all these folks manage to hold down so many board seats while also working so much. Decision making, especially in technical companies, has to be delegated out of the C-suite.
That’s my observation at all the bigger companies I worked for. The manager of the manager of the lowest level workers has no contact with the workshop reality. They live in the PowerPoint world with hockey stick growth slides and ideal project plans. There were exemptions, but very rare. One level above has absolutely no touch with reality without any exemptions. Some of them were able to participate in meetings from the shower with enabled camera in the past… I doubt these are working hard.
When you can be CEO of multiple companies at the same time _and_ be on the board of several other companies, being CEO clearly isn't a full time job, at least for the people that aren't just focused on being CEO of a single company.