There's actually a lot of good edu stuff on YouTube these days, many of it made by independent creators.

The problem is, of course, separating the good from the bad. My nephew learned a ton from YouTube (he's 8 now), but it's a lot of work for parents to ensure that the material is good and correct, and actually child-appropriate. (And his parents are both teachers, so they have a bit of a leg up on their ability to evaluate educational quality.)