The problem is that many consumers might not even be aware that its a decision worth researching. For example, in some areas of the US it is cheaper and quicker to order online through Walmart than it is through Amazon. But most users order through Amazon by reflex, not even considering if there is an alternative.
Advertising helps here. It tells them "look there is an alternative. Consider it!"
People go to Amazon for online shopping because Amazon pays to have a bigger web presence through advertising than WalMart does. Had there been no advertising on either end, you'd have a level playing field where people would have to discover the best / cheapest / most efficient online shopping on their own.
Seems strange that you think advertising helps here when you also claim that people are responding to advertising with negative outcomes.
* My local news paper's webpage (which i pay for).
* HN which does not have ads
* neogaf which do not have ads
* youtube / twitch which I pay for (and block whatever else with ublock)
* Email (through google apps which I pay for).
On the rare occasion I visit something else I make damn sure to to have ublock / noscript active.
When it comes to apps, I pay for them. If there are no pay/ad free version I don't use them, it's that simple.
I haven't had regular TV in over 10 years and I surf with ublock origin yet I can still find the things I need to buy.