I work in digital marketing, and can tell you that it's not very exciting. The best performing paid ads are text-only and served to the user on the search results page and usually not on third-party websites. They're the ones that can be A/B tested the fastest, and the 'creative' part of it is very much metrics-driven. That's where the bulk of ad spend goes, as it has the highest ROAS.

Plus, users who are actively searching for something are more primed to respond to an ad that appears on the results page, as opposed to an ad that pops up in the middle of a news article they were reading. Users for the most part don't seem to like stuff with animations, or heavy graphics in their ads as they're distracting.

I have noticed more interesting ads on newer mediums (media?) like Instagram stories or Snapchat, which are image and video-centric. The targeting so far seems quite good, as I usually see ads for online courses, creative stuff, design tools.