If we ban billboards at least the the countryside will look nice
So banning billboards makes advertising less efficient. In theory, anyway.
I'd much rather be fed efficient advertising on a billboard than have to worry about more astroturfing, that stuff is insidious. Cure substantially worse than the disease once advertisers have to deceptive and have even bigger incentives to hide than they already do.
And much as the anti-ads people want to skip the point, nobody ever even established that advertising is a negative thing that advertisers need to be harmed for.
Advertising already makes extensive use of astroturf campaigns and product placement.
Cable TV started out with no ads, as a major selling point over broadcast TV. Then they started advertising because they figured they could make more money that way. There's no reason to believe that advertisers will ever refrain from introducing ads when there's money to be made by doing so.
Then put them in jail, that's why we've built them.
Know what we have instead?
Peace.