I guess look around the world and see what's working? Unfettered capitalism wouldn't work, and cronyism isn't unique to capitalism.

Unfettered meritocracy doesn't work either. Say I'm born smart and ambitious and become a captain of industry. Why do I "deserve" to make 100x or 10000x more than someone who is working hard but not smart or ambitious, or someone who is wildly creative in a not monetizatable way? And how do you even ensure all kids get the same starting line to actually have a meritocracy, if you are enforcing capitalism? 100% inheritance tax maybe, and the money allocated out to everyone?

Maybe all these systems are ideas - capitalism, socialism, fascism, meritocracy, and none could be achieved in real life, because we aren't living in a controlled test environment.

On your specific question, I think cronyism and inheritance are problems that transcend capitalism, but if you could somehow magically disappear them, meritocracy would reveal its faults, there isn't a perfect system. All we can do is try to think about what we want to achieve (environmental restoration, a healthy population, a vibrant marketplace that serves everyone not just a few) and try to incrementally get there.