Your arguments rely on the sole premise that socialism was either not achieved or failed in the Soviet Union and China. But the historical facts prove otherwise.
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The Bolsheviks succeeded in their revolution and managed to establish a socialist state. The "collapse" of the USSR seventy years later is irrelevant and does not change this fact.
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Marxism-Leninism is realistic and not idealistic. It prioritizes the consolidation of the revolution and building socialism at home before getting drawn into volatile revolutions abroad.
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The soviet workers did have democratic control over their production. Not as individuals, but as a collective. This control was exerted through so-called Primary Party Organizations present in factories, farming collectives and neighbourhoods. Similarly, China has enterprise party branches which are crucial for management.
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China has shown the opposite of backpedaling into private enterprise. Since the start of this century, the state has been stricter in regulating non-public enterprises and directing them towards the social goals that are set up by the five year plans.
All of these points can be fact checked and there is plenty of academic research done on them. I can recommend for starters Roland Boer's works.
What happens when your revolution successfully topples the government, the corporations, how do you coordinate production and distribution?
Just like other socialist states have done in the past and presently: you let the workers control and manage the existing factories, farms and enterprises according to what they seem fit; you organize them and provide them with enough training and education. There are plenty of lessons from history in that regards which one can learn from. I don't know why you seem to think this to be a difficult matter.