Yeah... Then again I just use the DuckDuckGo bang !mdn and it searches MDN directly.
There's also devdocs.io which can be indispensable when using a lot of popular utility libraries and frameworks in the same project. Just having a single page with all the relevant docs is just a real blessing.
I remember visiting W3S like 10-15 years ago when first learning DOM manipulation etc at uni. But nowadays there's nothing it can give me that MDN can't, that I need to know.