I will grant that companies would lobby hard against an anti-advertising bill (which means it'll likely never pass). That doesn't mean you couldn't make one that's pretty effective.
But, again, the nature of advertising makes it quite easy to outlaw. Unlike bribery, where a congress person can shove gold bars into their suit jackets in secret, advertising has to be seen by a lot of people to be effective. Making it something that has to be done in secret will immediately make it harder to do. The best you'll likely see is preferential placement of goods in stores or maybe some branding in a TV show.
What you seem to be missing is that, in the end, it's all about risks vs. potential gains.
As it stands, advertising is relatively cheap and the only risk is to lose all the money spent on it.
Once it's made illegal, that formula changes massively since now there's a much bigger risk in the form of whatever the law determines - fines, perhaps losing a professional license or the right to work on a certain field, or to found and/or direct a company, perhaps even jail time!
You're right, it will probably still exist in some ways in some contexts. I bet it wouldn't be nearly as pervasive as it is today though, and that's a win. And if it's not enough, up the stakes.
Separately, I was saying that we can't usefully debate the pros and cons of such a vague proposal. You can postulate that some sort of vaguely defined prohibition would have no drawbacks, but any concrete policy proposal will in fact have drawbacks, and in some cases those will outweigh their advantages.
I think the same is probably almost true of advertising, though maybe societies without money such as Tawantinsuyu are an exception. But I don't think you can have merchants without advertising, because, like fraud, advertising is so profitable for merchants that they will do some of it despite whatever laws you have.
> I was saying that we should consider the possible enactment of such laws in the light of the knowledge that people will try to circumvent them and will sometimes succeed
That should always be the case when discussing any laws. If you don't consider that people will try to circumvent them, there is no point in considering punishment for when they do, and ultimately there is no point to the law.
> rather than assuming that, if advertising is prohibited, there will be no advertising.
As above, I would expect no one to make such assumptions.
> Separately, I was saying that we can't usefully debate the pros and cons of such a vague proposal.
I don't see why not. I suspect most proposals and ideas start vague, and by discussing their pros and cons and further refining them, we get to more concrete, more actionable ones.
> but any concrete policy proposal will in fact have drawbacks, and in some cases those will outweigh their advantages.
This is a truism, I'm not sure what value it adds to the discussion.
Just because some corruption always will exist, doesn't mean that there aren't societies which have enforced laws that are more or less effective.
This binary thinking doesn't need to happen in a policy discussion. We don't need a perfect set of laws or rules to make things better. We don't avoid having a law just because someone will violate it. For example, a speed limit is still valid to have even though most people will break it, some egregiously so. DUIs laws are useful even though people still drink and drive.
It just so happens that with advertising we can be particularly effective at curbing the worst offenders. That's because advertising is most effective when it's seen by the largest number of people. I don't really care if a company tries to skirt an anti-ad law by paying an influencer millions to wear their product, so long I'm not forced to watch 20 minutes of ads in a 20 minute video. An anti-ad law would force advertisers to be subversive which is, frankly, fine by me. Subversive ads simply can't be intrusive.