Marketing is built off the idea of myths.
Myths not in the lying or manipulative sense (although that can certainly be present in some marketing) but myths in the sense that we as humans don't see reality as it actually is.
This has been observed over and over again that we evolved to survive - not to be a machine that could see reality for what it actually is.
We never have the full picture, we never have all the information possible before we make the decision. What we do in reality is use shortcuts and shorthand to make that a decision we can live with.
Marketing deals with myths because a lot of marketing is based on human perception. Human perception takes less then 1% of information available, makes an emotional decision then rationalizes afterwords.
Marketing starts with myths - myths are a byproduct of the human perception machine.