Isn't all open source built from the time of experts? (Not experts in chess, but in programming, design, etc) :) I mean in theory, nothing prevent a profession

Isn't all open source built from the time of experts? (Not experts in chess, but in programming, design, etc) :) I mean in theory, nothing prevent a professional chess player to make a nice video lesson and share it for free. And there is no reason to assume this video would not be as good as videos made for money (just like it's the case for software)