And that's the thing. The ones that become mega-famous are typically the ones who have been around for an extended period of time - either through having spent the time building a single successful company (Bill Gates, Zuckerberg etc), or people who become well known for starting up multiple companies. If Bill Gates had retired 4 years after starting up Microsoft, how many people would even know his name now?

Rather than trying to identify people who've famously walked away after a few years and comparing them to the number of famous people who didn't, a far better measure would be to find random 20 entrepreneurs who have only been doing it for a couple of years and see how many of them are still doing it, either with the same company, or with a new company, in 10 years time.

It's a mistake to argue that the entrepreneurs you read and hear about must be representative of all entrepreneurs. It's quite likely that the ones most likely to become serial entrepreneurs will remain visible, and the ones who stop after a successful exit are less likely to remain in the field.