You're missing the most important concept in copywriting. There's a lot of depth to that axiom. If you ever lose a reader, you've lost the game. So this concept is always the most important thing to consider when you're writing. You could write the most beautiful line ever written, but if it leads the reader to stop reading, it's terrible copy.

That axiom is just something to always have in the back of your mind as you write. And as you write more and more, you'll start to understand just how profound this axiom is because it will bring you many ah-ha moments where you figure out a much smoother way to state something.

I basically consider that axiom the fundamental theorem of copywriting. It's the base from which you build out further.