Because what makes it useful , like media queries, can't be put in style attributes. Frankly this whole discussion is just as silly as claiming flex has nothing over table layout.
Then again one should aim to not even need media queries and make things responsive intrinsically, breakpoint-free, continuously. A design where things jump at hard coded viewport widths is not actually a great design.
Then again one should aim to not even need media queries and make things responsive intrinsically, breakpoint-free, continuously. A design where things jump at hard coded viewport widths is not actually a great design.
So at least that part is not so amazing.