ExpertsExchange was useful because it had a broad range of obscure technical information, and the ability to get specific questions answered, but it was spammy and a pain to use. StackOverflow came along, took the good parts of that model, combined them with a clean interface and an open community, and won.

W3Schools is useful because it's a good barebones reference that assumes zero prior knowledge of the subject, but it's somewhat shady in how it represents itself, and the information isn't always accurate/complete/up to date. X came along...

As far as I can tell, neither of the two sites you linked, or the parent article, are a good reference for absolute beginners, which is the only thing that will either beat W3Schools or force them to improve.