Comment by vkou

One broad view is that anti-trust is supposed to protect consumers, not competitors.

If a competitor can't produce a quality product that people will pay for, consumers aren't being harmed by the prevalence of a free good-enough product.

In a consumer-protection world where a free and open source Linux had 98% market share in the OS market, Microsoft or Apple would have no leg to stand on to sue its developers over anti-trust. In a competitor-protection world, they would.

The US views anti-trust through a very consumer-focused lens[1], the EU sometimes views it through a more competitor-focused one.

[1] This doesn't mean I agree with it, and there are obvious problems with trying to prove harm in a court of law, if no alternative exists.