I'm not surprised to see w3schools.com up there. I haven't come across it recently because of shifts in what I do, but it used to come up so often when I was looking for coding documentation. It was almost always useless.
If only it was merely useless. I know its reputation but it had some information that MDN did not have, so I used it this once in recent years. Turned out, the information was simply wrong and so I made a wrong decision based on that. (It might have been about favicon format support in different browsers. Presumably it was Safari that never had support for vector graphics whereas w3schools listed it as such, and it's not like you can just download Safari to double check.) Regardless, what I'm sure about is that I alerted them to whatever the problem was, but for me it was the last nail in that coffin