Greed is infinite, and is ultimately about power and control. If it were possible, I am sure there would be those who would own the entire galaxy, if for no other reason that to say it's theirs.
Even now, you have executives that earn multi-million dollar salaries, with super yachts and homes that they use for a fraction of the year. What's the point? There is little additional benefit from having a 100 ft yacht compared to a 200ft yacht, but there is a huge difference in the money you have to have to pay for them.
All those dollars have been paid to a single executive to afford such things has been done so instead of making goods and services cheaper for the customer, or by paying better salaries to the rest of the company's employees.
Executive salaries in the 60s were typically 25x the average salary.
Now they are more than 200x the average salary. More efficient production is not going to change this.