A planned economy has been tried. However, even after removing all market mechanisms, corruption amongst the party managed to shatter the union.
As much as Deng is hated, he managed to set the foundation of a mixed economy, which, as we can see by the great growth of China, was probably the correct thing to do.
Later adaptations by the CCP managed to incorporate precautions to prevent internal corruptions, and furthermore, bourgeoisie corruption to avoid the dissolution of China and shock therapy.
Furthermore, after the dissolution of the USSR, many communist parties followed China in pursue of a mixed economy, leading to growth and the betterment of society as a whole.
That’s not to say that China doesn’t have its flaws. Particularly in its neutrality and lack of action internationally.
In my view every industry goal should be to produce as much as possible, as efficiently as possible, with the best quality possible. Having access to a world market where you can allocate your production and have access to inputs really helps this goal. Limiting industries to a certain threshold of production dictated by a planned economy kinda hinders the development of production.
Until there is a global communist goverment that could plan the needs of the global population, a planned economy only hinders development.
This is my general view of things, but of course there are some nuances here and there, strategic industries should not operate by the same standards of a civil industry, etc…