I think big companies do constantly need to remind people of their brand with ads to preserve it. That's why you see Coca-Cola ads everywhere, despite everyone already knowing who they are and what they sell.
Plenty of businesses would die without ads, they would be naturally selected out of people lives because without the brain washing, they are just not that important enough.
Well, you at least levelled one of the playing fields (while also removing a huge eyesore, which I really like!). I think the business deals in the background play a very large role too, if not bigger than the advertisements themselves. By business deals I mean that many restaurants exclusively serve the coke or pepsi family of drinks. This won't change if we remove the ads, only strengthen, and the larger players have a bigger weight, so the field is still very tilted.
That plenty of businesses would die without ads, I completely agree. There's an entire business model of running a bunch of ads, selling a bunch of crap, then disappearing. I would say good riddance to these.