So, if no one competed to get ahead of competitors, by making better or cheaper products and to grab the available marketshare, we would just have better and cheaper products without it? Sounds flawed to me.
Not sure what you mean. People would definitely still compete on quality and price in a world without advertising: much moreso, because they couldn't just spend money for sales without improving their product. If they wanted to improve sales, they'd have to either get better or cheaper.