The OP didn't say that it has to work perfectly to work. Capitalism just has to be better than the alternatives and society needs to do its best to fight back against the corruption and cronyism which corrupts it.

Too often people want to abandon markets and replace it with something that solves some of the problems but introduce tons of their own, instead of fixing obvious problems within the current system that was otherwise working well.

The better solution is a bunch of smaller experiments being run simultaneously in large economies (Ala at the state level) to see what works best. Instead of pretending we can have a one-size-fits-all best solution for the entire world.