This is mostly due to social spending, which wasn't so high in the Soviet Union. People think of the Soviet Union as some kind of welfare state on steroids, but social spending was only about half of the current level in France as a share of GDP when defined narrowly and, even if you include food subsidies and enterprise benefits, it was still significantly lower. It was probably high relative to a typical, non-socialist country at a similar level of development, but not shockingly so. What made set the Soviet Union and other socialist countries apart from market economies was not so much social spending but the reliance on central planning rather than prices and the market to coordinate production units. It's actually a testament to the efficiency of a market economy that France can get away with so much redistribution, even allowing for the fact that it's not sustainable at current levels, without destroying its ability to produce wealth in the first place.