I readily acknowledge that literally is often used when a sentence is figurative; that's not the same thing. For literally to be used to mean figuratively the utterer would be worried that, but for the presence of "literally", the sentence might be understood to be literal.

I contend that the role "literally" usually plays is that of an intensifier. I believe it plays that role through ordinary application of hyperbole: the utterance "X is literally Y" is usually meant as "X is very Y; X is so Y it is almost as if it were literally Y; but of course you understand that it was not, in fact, literally Y - we're all reasonable people here."

In much the same way, when someone says "You left me waiting for days" and it's been a handful of minutes, we don't say "'days' sometimes means 'minutes'" - we say that people exaggerate.

I recognize that I'm disagreeing with at least one dictionary; I believe they got it wrong.

And I won't claim that there is literally no single person who in fact uses "literally" to mean "figuratively" - but I have never encountered such an example and I believe it to be rare enough that we can consider it an error, even in a descriptivist treatment.