>I'd call that luck. Wait until a bad or stupid actor gets to power.

See: their zero covid policy. Great at first, but the stuck dogmatically to it even after omicron, which led to massive deaths.

I'll grant that communism makes it easy for a single person to have all the power, but "one single person in power can ruin everything" is not exactly unique to communism, and I am unconvinced that it explains why communist nations tend to stay poor.

Happens everywhere, but the way power in communism works makes bad stuff happen many times faster. In democracy there is a long time until a bad actor can do real damage. There are policies and various mechanisms that prevent that(to a point). Even bureaucracy works to some extent.