We don't have real data about this to compare but I imagine that if your company is doing well you can make it work without stress. That's why you have thousands of employees and billions of dollars to spend. I don't think you are a good CEO if you can't see the stuff at a higher level and not rest well.
I think you might be conflating owner and CEO. Owners often don't have to work every day after the business is running smoothly and they have hired good people to manage it. CEOs have to work every day just like all other employees and they have different types of stress than the typical employee. Sure the CEO probably doesn't have to worry about money or about getting fired (mostly), they still have plenty of stress because their job is to always deal with the worst problem. The problem no one else can handle or wants to handle. Plus they have to worry about the business as a whole and they understand that if they screw up, 10s or 100s or 1000s of people are hurt.
No, I am not saying that the CEO doesn't work and he/she is in the beach all week. Also, it is impossible to generalize but if you build a good team you can focus in very specific issues, the major part are solved by your team.
I am not talking about startups, just about established and successful companies.
