I haven't had any luck explaining to my wife that advertisements are basically a sort of cancerous meme designed to deliver misinformation and manipulate you into wasting your money on products that focus more on self-promotion than quality or value. I just sound like a jerk and she somehow takes it as a personal attack
I think the thing to do is to focus on yourself rather than the person you're talking to: instead of saying to someone that ads are "designed to manipulate you", say that they're "designed to manipulate, and I know that I'm not always strong enough to resist being swayed to want to buy something I don't actually want or need".
Frame it as ads making you, personally, feel manipulated. Don't try to proselytize and tell people that they're being manipulated, because no one likes to be told that they're gullible and weak. So focus on how ads affect you, not on how you believe they affect the person you're trying to convince. Because even if you're right about how it affects them -- and you probably are -- it doesn't feel good to be told that.
So that's the obvious end and you can see pretty easily how it exists all the way up the spectrum from the extremely serious effects through to the utterly "well thats 30 seconds I'm never getting back" level of trivial.
The advertising industry has no regard for you or your family's or your community's mental health. None. This is clear to me and you can form your own view. Given I believe that, we have to run defence. And you do, I do, everyone does. "Kids, that is fake, that isn't real." If you never had a discussion like that with younger humans, be they your kids, extended family, friends or randoms then, I kind of wonder why not? How much defence should we be playing against it all? As much as we can is my answer. It's wrong not to make some kind of effort.
Where are you drawing the line for the health and welfare of your family?
Most of the time when I try to float the idea that advertising is making someone sad so that they make purchases, that person tells me about the Great Products they discovered through instagram.