What I'm wondering about, though, is the rest of these younger entrepreneurs: I understand that the older entrepreneurs of course make better decisions, but I wonder how much of these younger entrepreneurs (wrongfully) think they are just as capable, and thus something like Dunning-Kruger was taking effect.

I try to reflect this on myself, 26 years old and founder of a startup, and I am fully aware of my inexperience. I personally attempt to compensate that problem by gathering more experienced people around me, but in the end, there is only so much you can do about it. I do think, however, that knowing you don't know everything at least allows you to be more aware when you're likely to make a mistake.