It's a middle man is all imo. I have actually used it for css stuff, but for python (as a python programmer), I want SO or the actual documentation , so its annoying when what I consider ad-driven content gets in the way of my search.

I can tell you why I hate them... explanations are usually incomplete or wrong in some cases. Examples often use antiquated browser code when the answer should just be vanilla JS. They don't use best practices... like ever. They don't generally use modern code (don't use arrow functions or continute to use var). MDN is pretty much better in every way.

For CSS and Javascript I've found MDN to be more comprehensive.

I do use w3schools for SQL syntax though - I haven't found any better resource for this, and generally Google gives me MSDN articles about TSQL which are usually of no use to me.