w3fools used to be much more scathing about w3schools, but they’ve had to really take a step back in their ire because it just isn’t any where near as bad as it used to be!
In the good Ol’ days, they used to teach PHP with awful security flaws, leaving lots of web forms open to SQL injection, so people that knew better were right to really slam them for it.
These days it’s actually a pretty great beginner resource (which even w3fools acknowledges), and the built in code editor is really handy for experimenting with ideas. I wouldn’t dissuade anyone from checking w3schools as an initial point of reference - especially because MDN is not that beginner friendly and it actually takes a reasonable amount of JS knowledge before it makes much sense. Obviously, once you have that knowledge under your belt, MDN is kinda the gold standard for JS docs.