Theres a natural tension here, because in order for this to be true you need a diverse market with many competitors. But that is bad usually, because it's extremely inefficient, so it gets optimized out. The monopolies we see are indeed an optimization - the natural climax of a developing market.

Consider payments: you do not want to carry around 100 different cards and trinkets just to pay for things in your daily life, right? And for merchants, they do not want to make deals with 100 different companies to accept payments, right? So what's the end result?

We see the monopolies in the US economy because our economy is very efficient. It could be even more efficient - consider, for example, how much time and money could be saved if only one phone OS existed.

But then of course that's bad for you, the consumer, because then these huge corporations rule your life and can essentially do whatever they want.