What you cite is one factor. Another factor is access for students. Once upon a time, curious students had two choices: buy books to learn on their own; or go t

What you cite is one factor. Another factor is access for students. Once upon a time, curious students had two choices: buy books to learn on their own; or go to whatever low quality teachers they had. Cheap internet, YouTube, LibGen, other resources help students as long as the latter desire to learn.