Would be true if individuals were rational. We are not. And without interaction and dependence on others nothing very interesting is ever found.
Well explained here - https://www.edge.org/response-detail/25426
Well explained here - https://www.edge.org/response-detail/25426
Nor is rationality itself necessarily an ideal end goal. In fact, this obsession with rationality (exemplified by sites like Less Wrong and in general by scientism-adherents) is itself a perfect example of my point - a group of individuals stuck in their worldview, incapable of seeing beyond the walls of their own local culture.
For all we know there are a lot of top notch dreamers sitting in the Serengeti today that are going to die there because the groups they are surrounded by can't help them in anyway.
Without the right group surrounding the individual good luck realizing dreams and changing the behavior or thinking of any other group.
And for a contrarian example, consider someone like Nietzsche. Probably in the top 5 most influential philosophers of the past ±150 years and yet he wrote most of his books alone while wandering Europe. He also published most of them at his own expense and didn't have much of a readership until near his death, at which point he had gone mad from syphilis. There was no group around him and no community helping him. Yet here we are, deeply influenced by his ideas.