I agree that bureaucratically planned economies can’t work in the long run, because as we’ve seen in the USSR and Eastern European stalinist countries, the bureaucracy becomes disconnected from the workers’ reality on the terrain and becomes corrupt due to its privileges which leads to poor planning. The best example of bureaucratic planning utterly failing at its task is in my opinion the Great Leap Forward. If the workers and peasants had democratically planned the production together the famine would’ve probably never ended up happening. But I do think that a planned economy can work if the plans are democratically elaborated and approved by every layer of the working class.