The biggest blow to Google wouldn't be to break it up into lots of small companies, you just need to separate the advertising business from everything else and you've effectively neutered the monopoly. Google's genius isn't in hiring the best engineers to providing a ton of services, it's in convincing people that they're not an advertising company, and that is where Facebook has been falling out of favor recently (I'm guessing that's why they bought Instagram, and why Google bought YouTube).
This is a supposition - while perhaps it seems to makes sense, seems true, “must be true”, it doesn’t mean it is true!
Unless you worked on search quality at google you really aren’t in a position to know if, say, google cloud, or android provides useful signals to search (outside of the signals they’d collect anyways if they were different companies).
One thing people are obscuring is just how crazily effective AdWords are. They work for the advertisers, and they earn google like 70+% of the revenue. Confirmed via sec filings which does break that out. Go play with creating an AdWords campaign and try to infer just how much data google really needs to deliver those ads - it’s less than you’d think.
In short: this overall move is more wishful thinking than solidly reasoned. Surveying the field of streaming video, given the amount of studio driven consolidation, is there really a tons of competitors being held down and will spring up? I am skeptical.
But my thinking was that if you simply cut off advertising all the products still have massive marketshares and could lean on each other, as long as some succeed. Not to mention investors probably willing to prop up such a massive aggregate marketshare (one only has to look at Uber).
If you 'silo' them, success of one division of previously-Google won't lead to all of them dominating.