It's really simple: Corruption. The former FTC Commissioner, Joshua Wright, was actually paid to fabricate academic studies claiming Google wasn't a monopoly, which Google then used as 'independent' expert testimony. Google's funded about half of Congress in some way or another. Dozens of Googlers held high-ranking positions in the Obama Administration's White House. (Including many relating to tech, such as the head of the Patent and Trademark Office, the White House's CTO, etc.)

Google has invested significant money, resources, and manpower in the United States government, and at least, during the Obama administration, was perceived as an ally to the general agenda. We have yet to see how much changes under Trump, the rumor is Joshua Wright is already back involved with the FTC, but the Trump administration has lagged on actually getting all these agencies re-staffed, and who knows what'll actually happen: https://theintercept.com/2016/11/15/google-gets-a-seat-on-th...