Note, it's not illegal per se. It's not illegal because of a de jure monopoly. It's not even illegal because of the number of users they have. It's illegal because Bing, Yahoo et al are not as relatively successful.
It was the same with browsers. Microsoft were hit for bundling. Apple haven't been though they've done identically the same thing. Why? Because enough people bought Android phones in the EU.
I do find it dubious that, effectively, the primary criteria for illegality is not what the defendant did but what some other actors didn't do. Seems wrong to me.
And it's true - they are. By design.
Also, Many people here seem to forget that we do not, in fact, live in a completely laissez-faire capitalistic society for good reason. Especially compared to the US, the countries in the EU do not view unfetered capitalism as a 'good and just' thing.
You win by being the natural favorite of users' free choice of exchange, not by eradicating the ability of others to compete. We need more penalties like this for those usurping the concept of the market.
In that case, if you win, others can still win as well.
Antitrust: Commission fines Google €2.42 billion for abusing dominance as search engine by giving illegal advantage to own comparison shopping service
Antitrust rules. The EU decided they broke them. Whether you think they did or didn't is irrelevant.
This is more about politics and EU bragging itself, for doing something "fair", for the people.
Except the carrot is only dangling on the stick and as a donkey, you're not allowed to ever get it - because the moment you do, you stop moving forward. Hence it's imperative to a) convince people they can win, and b) ensure they don't. Because it's not the players that are socially useful, but the game itself.
This is literally what the board game "Monopoly" is about. Like that, only you can't quit the game and are dependent on it for survival.
A 'winner' would mean the end of it.