Guess what - Leonardo wasn't a superstar back then but he'd worked in Verrocchio's workshop, a workshop that was one of the best in Florence. He learned an immense level of technical skills there. Then he also was a master in the Guild of Saint Luke in Florence. Then he painted the Adoration of the Magi (which was never finished, but whatever). Then he made a silver lyre, which the medici family sent to the Sforzas for a peace accord.
So the modern equivalent of this is something like (and I'm making this up clearly) someone who started at a regionally famous company at a young age, worked there for years to cut their teeth, meanwhile was a regular presence at conferences or Meetup groups in the area, who then worked on a company that generated some buzz but didn't succeed ultimately, and then one of their VCs introduced him to another company.
So, not the same as a person with no experience to show for getting a daylong interview with fizzbuzz and a take home project. In fact the "interview" probably took days to weeks in that case!
edit: And yes, of course I don't think that's a good way to conduct interviews. But it sure as hell wasn't a better or more efficient or more equal opportunity system back then. Progress has happened since then. It just should be happening at a much faster rate now and it's not.