Sure, I could believe that young people have a better chance of founding a $100B business. But I (and almost everyone else thinking about founding a startup) is

Sure, I could believe that young people have a better chance of founding a $100B business. But I (and almost everyone else thinking about founding a startup) isn't going for the $100B moonshot, just becoming your "everyday" successful entrepreneur with a <$100M exit is quite enough, and I find it very plausible that 45 year olds are much, much better at building those.