Even better, we should ban all ads.
Ads are a completely legitimate business practice: I make a product or offer a service, so I want people to know about it.
Bans on targeted ads are not about the advertising, they are about the privacy concerns resulting from the data collection that is the prerequisite for targeted ads.
Perhaps specialised 'discovery' services would pop up for people wondering what sorts of new stuff/services was out there?
On the surface of it, I'd assume that if reaching out to customers to 'let them know you exist' via advertisements was prohibited, the amount of innovation and investment into products would decrease. But at the same time, the amount of money allocatable to product development within a given budget would increase, as you wouldn't have to expend so much on marketing (which in some cases, dwarfs the cost of R&D). But maybe the markets would just adapt anyways. Seems a fun thought experiment.
In theory a perfectly targeted ad might produce some value for me, but in practice people who make shit products have more money to throw at ads, making Sturgeons law even worse.
"Targeting" and the associated data collection is much easier to determine and codify into law.