As a user, this is what I want: The ad network provides the javascript, not the advertisers. No ad-hoc javascript provided by each advertiser. They deal with a standard API where they provide the content using pre-configured blocks of code. Like "we provide this standard tracking tool, this standard slideshow/animation system, etc".
It's not really the advertisers providing the JS, it's that there are tons of adtech platforms and everyone just mixes and matches.
This is why you have 1 tag that loads dozens more because each agency is using a different system to serve an image or track an impression. There are some standards around formats but the actual tech delivery is terrible and this industry (for all the great tech that is actually built) just seems to have major problems at making things that work well. Probably because the consumer has never really been the major focus.
This would be sweet and all except for the fact that ad networks typically don't care about a) providing proper stats and b) detecting display/click/affiliate fraud.
