If some person isn't willing to do company building because they are already at the cap so it won't make them any more money, that just means that someone else will do that. We have a planet of 8 billion humans; there's no shortage of human talent.
This is an untested assumption, as it takes quite a bit of CapEx without return to start a rocket company, or a tunnel boring company, or a car company.
There's thousands of Einsteins kicking around. The majority of them are in places like India and Africa, not having access to resources that would allow them to realize that potential.
