Lenin ended any oppurtunity for none CPSU members to be elected to the Soviets and banned factions in the CPSU in 1921. He then eliminated opposition with the Cheka. Even before that the Communists acted under “war communism”, which meant killing anybody not 100% in line. That very much included Machnos work in setting up a Soviet Democracy in Ukraine, due to them being Anarchists. Stalin then abolished the Soviets in 1936.

The Soviet Union had a bit of it, in the very beginning, but it failed and turned into a statist dictatorship. That is why Stalin ordered the Anarchists to be killed in Spain as well, the Prague Spring got crushed due to moving into a more democratic direction as well as many other movements of worker uprisings.

Socialism means collective ownership of the means of production. The issue with the Soviet Union was that all means of production were controlled by the state. However there was no way in which the people controlled the state, since at least 1936 and argueably earlier then that.