Even in a digital world, monopolies bring clear downsides. The case of Google being able to simply create realities by way of Chrome the rest of the market is forced to follow is a good example here.

I agree that the common understanding of antitrust regulations has become a leaky abstraction, but the general idea is still completely sound to me: A corporation should never be in a position where it can actively suppress competition, or act in a way that is harming consumers without an alternative available.

> Are they regulating monopolies, preventing monopolies, pursuing an abstract notion of Justice?

I suppose all of it; opportunities to prevent some monopolies were missed, to the detriment of all, so regulating them is the only option left. In other cases, we can still act to actively work against emerging monopolies. And above all is clearly a notion of justice, without which democracy itself would be a pretty futile exercise in bureaucracy.

Put differently, what do you suppose the EU should do? Just let global mega-corporations have their way? Even if Google users by and large don't pay for the services, we're all aware they monetise off of users still. To me, this is an implementation detail that doesn't really make a difference to the observation that yes, Google is (and other big tech corps are) clearly in a market dominating position it (they) should not be in.