Ben Thompson from Stratechery has some good thoughts on what makes Google tricky to regulate:

- Google: https://stratechery.com/company/google/

- Regulation: https://stratechery.com/topic/regulation/

His vastly oversimplified point is that most anti-trust regulation focuses on supply. Owning all of the printing equipment and distribution networks in newspapers gave you leverage. Google is instead a demand-side aggregator (they don't own the content on their product, but own the choke point, which is the consumer facing user experience of having a single, simple, easy to use search engine).