I think what author said is explained in the article, as that such approach undermines small businesses which provide informational services. They won't be able to hire data analysts and researchers anymore, hence quality of information in info boxes will decline as information gets outdated. In other words Google is stealing data presenting as it's own taking all the benefits of embedding ads data
The consumer is harmed because there is no one incentivised to create new content, or at least the incentives are severely diminished.
In the story here the celebrity net worth data had to be created and this was worth doing due to the ad revenue. Making the existing data available to consumer is a benefit but the negative is the lack of new content. So now consumer have easier access to old, inaccurate data.