lmao. I unironically believe this though.
The more you concentrate power, the harder it is to keep bad actors from abusing said power.
What makes you think the power over those billion+ people is all "concentrated"? Could it be (gasp!) that the power is largely distributed among those people who overwhelmingly support that government? This is just capitalist-realism-brained misunderstanding of how communist parties work.
Most Americans approve of capitalism. Does that make it good too?
No, but that's certainly not what makes it bad.