It's not realistic in any scenario, that's just naive. Two main points to consider: 1. Most developed countries allow for some freedom of expression which rule

It's not realistic in any scenario, that's just naive. Two main points to consider: 1. Most developed countries allow for some freedom of expression which rules out banning advertising outright. 2. Advertising is generally effective in the sense that it increases sales to some extent. So as soon as just one player in a market starts advertising (which can't be prevented), everyone else has to do it too just to keep up.