No, the single thing that will keep people using w3schools is that they have managed to permanently glue themselves to the top of any Google search related to HTML or JS. Back when Google's site-blocking feature was enabled, they used mirrored domains to keep themselves in your results if you tried to block them. That is, you'd block "www.w3schools.com", and then your searches would have "wwww.w3schools.com" right up at the top.

It's really surprising to me, with abusive tactics like that, that Google hasn't penalized their page rank.