Really? I just did a quick comparison, and w3schools was much better than MDN. Try looking for info on the 'required' attribute of the input tag. w3schools has all the attributes in a compact table making it easy to find the attribute you're looking for at a glance, whereas MDN has a big long list. In w3schools you can then click on the 'required' attribute to get more info about it and see which browsers it works on. In MDN there is no info on browser compatibility in the 'required' description - you have to scroll down to ANOTHER table (there is not even a link to it) to see what browser it is compatible with! Come on, even back in web 1.0 we had links to stuff!

The reason that w3schools is at the top of the search results is that more people find it useful that MDN. Perhaps it isn't as cool with the hipsters as MDN, but for people trying to get things done w3schools is more useful in my opinion.