False premise, even more in the age of the internet. If you want to know what's the best x, where x is a phone, a flashlight, a toaster, then you can just google it anytime. In fact, it's very much the opposite: advertising enforces the status quo, since the biggest companies will be able to promote their product at a massive scale (bombardment is a better word) and monopolize attention. Small businesses get squat.

But that's not a problem, IMO. If something was good enough before, it's likely good enough still. If it stops being good enough, people will be prompted to look for alternatives, which they'll then discover. Given how it's nearly impossible to satisfy human beings, they'll start looking for options sooner rather than later.