The idea feels like sci-fi because you’re so used to it, imagining ads gone feels like asking to outlaw gravity. But humanity had been free of current forms of advertising for 99.9% of its existence. Word-of-mouth and community networks worked just fine. First-party websites and online communities would now improve on that.
The traditional argument pro-advertising—that it provides consumers with necessary information—hasn’t been valid for decades.
Right there are plenty of ways for businesses to get consumers to choose to use their product other than advertising which are far more conducive to consumers being able to make an informed purchase decision without being manipulated. But doing so would upend the existing power structures of who gets to sell more product, so disturbing the status quo just requires more political will than anybody really has.