Command economies don’t work. The USSR experienced growth initially because Russia was an economic backwater. That ran out of steam by the 1960s. The USSR never exceeded about 50% of US GDP, despite having a much larger population.

The USSR did some amazing things, for example in space. That just proves that a command economy can divert investment to specific ends. The USSR narrowly beat the US in several space milestones. We were close behind-such that we beat the USSR to the moon when their space program stumbled. But at the same time we developed advances in electronics, medicine, chemicals, etc., that weren’t even on the USSR’s radar. And we were doing all that while dedicating far less of our economy to investment (versus consumption).

Soviet industry was also breathtakingly inefficient. The USSR required five times as much energy to produce on unit of GNP than the US: http://pure.iiasa.ac.at/id/eprint/3500/1/RR-91-07.pdf. The Soviet Union had massive oil and gas reserves. But using vastly more concrete, steel, and energy to produce less durable goods than the US wasn’t sustainable.