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.
Personally I’ve been of the opinion that advertising, at least in its current form, should be illegal since I was about 15. I’m not 100% sure if it should be completely illegal, or just very heavily regulated. Even after all those years, I’m still baffled nearly every day that people around me seem okay with current advertising.