Why does the distinction of direct vs indirect matter when the question is about opportunity costs of deploying talent to potentially more fruitful endeavors?
Because a search engine that almost always finds what you are looking for is a fruitful endeavor. A website that lets me keep up with my extended friend circle is a fruitful endeavor. A website full of educational videos (and yes, a lot of mindless entertainment) is a fruitful endeavor.
By focusing on how they are funded, you're losing track of the fact that these companies provide incredibly valuable services.
By focusing on how they are funded, you're losing track of the fact that these companies provide incredibly valuable services.