Flippanarchy

They fundamentally did, repeating that they didn't like a mantra isn't a point, nor is said mantra justified by claiming it's "obvious." Again, public ownership was the principle aspect of the economy, and the working classes were in control of the state. This is socialism as it exists in the real world, in concrete form. Both Is the Red Flag Flying? The Political Economy of the Soviet Union by Albert Syzmanski and This Soviet World by Anna Louise Strong are good places to start with looking at how the economy of the soviet union functioned.

An excerpt from the latter:

Several elections which I attended will show concretely how soviet democracy functions. Four election meetings were held simultaneously in different hamlets of Gulin village, which had no assembly hall big enough for all. One of these meetings threw out the Party candidate, Borisov, because they felt that he neglected their instructions; they elected a non-Party woman who had displayed energy in improving the village and were praised by the election commissioner—himself a Party member—for having discovered good government timber which the Party had neglected. The central meeting in Gulin expected 235 voters; 227 appeared and were duly checked off by name at the door. There ensued personal discussion of every one of nine candidates, of whom seven were chosen. Mihailov “did good work on the roads.” The most enthusiasm developed over Menshina, a woman who “does everything assigned her energetically; checks farm property, tests seeds, collects state loans.” Dr. Sharkova, head of the Mothers’ Consultation, was pushed by the women: “We need a sanitary expert to clean up our village.” The incoming soviet was instructed to “increase harvest yield within two years to thirty bushels per acre, to organize a stud farm, get electricity and radio for every home, organize adult education courses, football and skiing teams, and satisfy a score of other needs.

It may not be your preferred model of socialism, but it was real, and qualitatively different from capitalism. Trying to claim it isn't the same as the "pure" socialism in our heads doesn't change that material reality, socialism isn't mystical but a material process.