Not "some sort of willful ignorance". It just requires "ignorance". I think most of us know someone who thinks that reality TV is ... well, reality. "It says it in the name".
> Show a kid a celebrity pushing something and they can tell it's fake
Perhaps you have very bright kids. My kid will ask me to buy two of whatever that person is pushing. He's simply not equipped to handle marketing at any level, yet.
I know he needs to be exposed to some marketing while I'm watching along to talk about it so he isn't completely defenseless against it later, but I don't think that time is quite yet. So far, I'm going with his being able to separate "real" from "pretend" as a minimum.
Show them how it is done. How one can cut, edit and change the sound.
Ask who did it, for what reason, for which audience, to what end?
Equip them with the tools to question the things they see. Then they have the means to engage with marketing.
It’s a long road. There will be glitter and cheap plastic toys along the way.
I know adults who voted for Trump because they believed the apprentice gave them an unvarnished view of his character and decision making prowess in the real world. My own grandmother would cite episodes of the show.