What are better ads? Are they ads that really connect with you? Do they change your behavior in some significant way? What makes ads better for the consumer? What makes ads better for the marketer? My answer is that what's good for the marketer is not good for the consumer. Google is optimizing for the marketer (getting better ROI). As long as consumers are told the ads are "unintrusive" they must be good too right? When marketers have a really strong ROI, they can get their ads out there and influence customer behavior. That type of influence is not good - and does not make it better for consumers.
Useful and obtrusive are not mutually exclusive. Is it useful to have only large companies with large ad budgets peddle a slight iteration to their product line as "the next best thing", while smaller companies with a really great (superior) product don't get the exposure. The smaller company would have lower margins because they invest much more in superior materials, QA, R&D, etc. Where the larger company has an advantage because they invest more of their margin on ads. Note: I have an "MX Performance" and I would not recommend that line of mice no matter what the ads originally said.