I think the main problem with online recipes is that there's a lot of stuff that "cooks" and "people who cook" learn that carries over VERY STRONGLY from dish to dish that is just totally absent from online tutorials. Things like what done (but not dried out) chicken looks like, and how to position chicken in a pan so the thicker parts get more heat, and why your chicken went right from "looks plain" to burned with no maillard reaction.
I think foods/culinary courses should be mandatory in high school. I took one as an elective, expecting it to be a blow-off class, but I ended up being shocked by how much I - honor student and all that - didn't know about browning hamburger, much less actual cooking. I ended up taking the subsequent 3 classes in the "foods" line.