The argument is that employees and shareholders can vote with their fleet by leaving the company or selling shares. That's not usually a practical option for most citizens of any given country.
The best performing form of government is benevolent dictatorship, until it isn't. Liberal democracy is generally accepted as the best compromise,
By who? Certainly not by the best performing nations.
with the biggest strength being the ability to remove non performing leaders / governments, in theory at least and we know how well that works out in real life.
"liberal" "democracy" is just an unachievable ideal used to mask varying degrees of oligarchies, much like "classless communism" is just an ideal and not something actually practiced by any communist organization.
I would really like to know what systems the CPC has to prevent incompetent / malevolent people from gaining powerful positions and abuse their power. I'm sure there are checks and balances in place, but it would be nice to know more.
The National Congress has 2977 members and appoints the executive power (politburo). Independent of either, the Supreme people's court is the highest power in the matter of law.
While China has been blessed with competent leaders for decades, that shouldn't be taken for granted.
It almost can, because the above system is very corruption/damage resistant. People become congress representants from a pyramid shaped voting structure. Then, they need to convene a majority to elect politburo officials.
So to create an awful high level leader, you need to brainwash a lot of locals + low + mid level politicians to all vote for the useless guy. Then, that useless guy will be at the same level with a bunch of charismatic and skilled people from other provinces/committees, where he will stick out as a sore thumb.
A system like this doesn't fully eliminate corruption (no system can), but it is the best compromise to get something done. China has had corrupt politicians, but they're forced to constantly walk on a tightrope, also it is very very uncommon that corrupt politicians are garbage at all their tasks. Usually, they perform acceptably or are even very skilled, but skim off proceeds on the side. No amount of executive power can prevent a politician from being charged by the judiciary, which has its own independent investigation teams. There is not even a sitting president exception.