That would be a desirable action but look what happen in the end of 90s to Microsoft. It was about to be broken up and in the very end it didn't. They become dormant and polite only to strike back some 10 years ago with Windows 10, its telemetry, ads and cloud services which are being pushed onto users whether they like or not. And somehow, no regulators decided to step in to clean up this company's behavior - everyone seems to be ok with what MS is doing. Whether it's the US or EU. I take that the business and lobbing goes extremely well in both markets.
And because of this, I don't believe that the US is able to break Google or the other flagship companies despite of reasons existing for such action.