Advertisements have side effects, such as bringing lightning or hiding ugliness. Don't confuse the side effect for the desired effect: if advertisers found out

Advertisements have side effects, such as bringing lightning or hiding ugliness. Don't confuse the side effect for the desired effect: if advertisers found out how to make ads cheaper workout reducing their effectiveness, but at the expense of secondary effects, they would. From your description, it sounds as if the city is ugly and that advertisements cover that up. That's not a reason to long for advertisements, that is a reason to long for a nicer city.