This has nothing to do with what I wrote. Whether or not people work "in a distributed fashion" is unrelated to whether or not those people have a team they see in person on a regular basis, contribute to public forums and chatrooms, or advance in their careers via collaboration with colleagues.
For what it's worth, most professional developers don't contribute to open-source on any regular basis. The ones that do often work in big companies, which then choose to open-source their work. Regardless, working in "a distributed fashion" is not the same thing is posting to forums that other people can see. And it's a rare company where everything you need to know is captured in public code. Usually that's just the table stakes -- the most valuable engineers are walking around with encyclopedic business knowledge in their heads.
The core fallacy I am rebutting here is that everything you need to know is just out there, freely available on the internet. Even in the open-source world, that isn't true.