Thanks to the trifecta of ubiquitous smartphones, pervasive Internet and no-holds-barred data mining, I'd argue that the tech landscape we inhabit today is very different from anything we've ever encountered.
Say a startup does create a better product than Google or Facebook, it can't charge for it, because everything is free. It certainly can't monetize it better than Google or Facebook because they have infinitely more data on users than any startup can even fathom. It has to go through Google's and Facebook's "gates" to find and retain customers.
Those precious few that do manage to pull off the impossible, like Whatsapp, will be quickly bought over by Google or Facebook. Thus closing off any gaps that existed in their defense and reducing the possibility of independent competition even more.
Any meaningful analysis of digital monopolies needs to understand this instead of just relying on past examples.
Edit: I'm not saying the EU is right, or that their motives are kosher. Merely that we need to do a comprehensive forward-looking analysis of Google's dominance, extrapolating from present data and trends. Using past data alone strikes me as lazy or self-serving.