What's the end game here? A future ruled by 400 year old Zuckerbergs and other multi-trillionaires? Much of the progress in society is possible only because p

What's the end game here? A future ruled by 400 year old Zuckerbergs and other multi-trillionaires? Much of the progress in society is possible only because previous generations eventually die off. What happens when that's no longer the case?