These countries typically ban alcohol, gambling, children and pharma ads. They still let a large number of ads through.

Well those sound like a great place to start.

Some of us actually go as far as ban billboards, electronic billboards, or even during elections - some counties in Germany limit all kinds of election related propaganda to a few large billboards at the entrance roads, and the rest is kept clean from the bullshit.

They didn't start out banning those ads. Those ads were banned because they were found to be more harmful than they are worth. We've come to realize that much of the ads we're subjected to these days are also harmful, so it's natural for us to want them banned as well.