> HOWEVER (I can feel your hatred), there's a difference between motivating people to aspire to better things vs simply making them feel shitty about themselves so they'll buy your crap.
There are lots of different ways to motivate people. Lying is one of them. Making them feel bad about themselves works too. I don't support either of those approaches.
So to use your example about the gym, I strongly dislike most fitness/health advertising for the very reasons you state. If I were to run ads for that industry, I'd focus on the effort of regular everyday people. I wouldn't show impossibly perfect (and mostly photoshopped) people. I'd show people from across the whole spectrum pushing themselves, waking up early to hit the gym. I'd focus on health, not "beauty". On working out so you can have more energy, fewer health complications, greater strength, etc. I wouldn't run ads that tell you "you should work out because it's the only way you could ever look like this model over here".
But that's just me. I don't know if my approach would work, because I haven't had the opportunity to try it yet. (Not a lot of fitness brands looking for an ad agency in Northern Ontario.)
People have dissatisfactions, but only advertisements have the audacity to point them out as a complete stranger. Even if a loved one did that, you might recoil. when people are unhappy about something, they will share it with someone they trust if they want to talk about it. Advertisements get a free pass to nose into your life and be your mother? Please.