Even in cases where full-blown communism is achieved, it’s not possible to stomp out capitalism entirely.

Example: You and I both receive our weekly rations from the state. I trade my bread ration for your chocolate ration. We both benefit. Free trade capitalism is restored, at least at this hyper-local level.

That’s why communism can only persist at the barrel of a gun. It’s antithetical to the way humans operate. Black markets always boom in communist systems. So long as there is any human autonomy left whatsoever, free trade finds a way.