That final line comes after the aforementioned explanation, not in place of it as OP suggests. The point, as many others have offered in this thread but those

That final line comes after the aforementioned explanation, not in place of it as OP suggests. The point, as many others have offered in this thread but those set on hating W3Schools at all costs are determined to ignore, is that they provide a succinct explanation of web technologies for the relative layman. Its existence doesn't detract from MDN or any other resource, meanwhile it provides a demonstrable service. That seems like an odd crime to warrant strawmen attacks.