If ads were merely about being informative, they would be boring. But ads want to manipulate, so they have to be flashy and appeal to your emotions.
They pollute your mental headspace, and have no place in a healthy society.
Let's ban billboards. And then let's follow that up with a general purpose ban on paid advertisement.
Advertising is how small and new companies can reach customers. It's how monopolies are broken. It's how progress reaches the masses.
Yes, it is willfully intended to change people's behavior. So are many of our posts on HN. That is an important purpose for communication!
What they should not be able to do is pay people, who have a media or influencer "brand", to say things about a product or service. Or pay media for a time slot during which a corporate agent spouts propaganda about the company's product or service. Or send a product to a reviewer as part of a contract for a review, even if it's supposedly a "fair and honest" review.