Dirty secret is that FOSS is a product of capitalism and nothing else.
A bunch of nerds being allowed to own and control the means of production created personal computers while the central planners in both communist countries and big companies both thought it was a dumb idea. A bunch of nerds being allowed to own and control the means of production meant that someone could decide to release their product free with source code. Private ownership of intellectual property such as source code allowed people to release their privately owned code under a license specifying that changes must be made public.
From there, the proof in the pudding is in the eating. How many FOSS projects do you use, and who made them?