It seems confusing to me.
Take Bill Gates for example, he started Microsoft when he was 19/20, a multimillionaire by age 23 and a billionaire by 31. Why stay with the company? Why not sell when you have a few hundred million and live comfortably for the rest of your life? I don't get it. How much money does one person need? I imagine at a certain point it has nothing to do with money and is simply about power.
Isn't the idea behind starting a company, inventing a product or in todays world, creating a website, to become so rich and make so much money that you can live comfortably for the rest of your life? To retire early and enjoy the world around you and no longer have the stress of a job?

I see all the billionaire people who just stay with their company so they can keep making billions. Why? It has to be about power.
Listen, I don't really care either way. It's their company and more power to them for growing it their way. I just question the motives behind it.