I didn't learn artificial neural network stuff from there. I knew those concepts but I didn't know the matrix formalism applied to it. So this was really nice to understand why GPUs are good for this. Math-wise it was really nice watch.
The web has allowed the sharing of high quality content across the world for little to no cost, but has also created so much noise for the average user that they have little to no hope of finding the high quality content on their own. Comment sections across the web fix this problem by promoting producers that offer a superior product. This encourages everyone to make better content.
In some ways, it is a "rich-get-richer" effect. But creators like 3B1B expend a lot of time and resources to do what they do, and the word of mouth he gets is an acknowledgement that the work he does is worth the money and views we provide.