All social systems require concerted effort to maintain. There’s no such thing as a magical system that runs perfectly forever as soon as you set it up. There will always be antisocial people who constantly work to undermine any system.

What capitalism does (that other social systems struggle with) is to give many types of antisocial people a productive outlet, at least for a while. They can exhibit their competitive drive and produce new products which benefit society. But when they become anticompetitive we need a functioning antitrust system to kick in and break up their companies. We used to have one but it was dismantled. Now Lina Khan is trying to rebuild it.

This is not even exclusive to people. Look at nature. Nature is full of parasites. Countless species of them. Take for example cuckoo bees which infiltrate beehives and consume honey while reproducing but doing no gathering work of their own. If the worker bees don’t destroy the cuckoo bees their population will grow so much that the hive will collapse due to excessive food consumption and lack of corresponding production.

Other systems (feudalism, Stalinism) allow antisocials to reach the highest levels of government where they can inflict enormous damage to the country by engaging in corruption. This is akin to letting the cuckoo bees run rampant in the honeycomb. In particular, the legacy of the Soviet system is now the murderous kleptocracy of the Putin regime. I’ll take any western capitalist liberal democracy over that, any day of the week.

Yes, capitalist democracies can also have corrupt people reach the highest levels of government. But that doesn’t give them absolute power over the economy the way other systems do. So the damage they can deal is greatly limited.