A few things:

First, definitions of soviet society, economic life and the country's political structure that try to claim the USSR didn't practice "real communism" are basically leaping right into the no true Scotsman fallacy. It was communism, or a reasonably well enough attempted recreation of the original dogma to be effectively called communism, and it was on the whole an abysmal social failure that even in its real accomplishments achieved them at far higher cost than would have been necessary. Sure, you could also argue that no western country practices true capitalism as your average hardcore libertarian would define it but the degrees of communism and capitalism practiced by both the USSR and much more market-oriented countries respectively were close enough to the "ideals" of both systems to get a solid idea of which is more workable for human society and good human development. The results were extremely divergent, and communism unarguably showed itself to be a failure.

Second, the soviet system was worse than its Tsarist counterpart. The comparisons to the Tsarist system that predated it really don't do justice to the enormous human tragedy unleashed by the Bolshevik revolution and Stalin's later rule in particular. Virtually every single element of repression, misery, poverty and death by government-caused means greatly expanded under communist rule. The Tsars had prison camps, yes, but the soviet GULAG dramatically expanded the brutality and size of the communist version, and the number of reasons that could get a person incarcerated in one of these camps expanded enormously from how things were in the last years of Tsarism. There were famines under Tsarist rule too, but the size and frequency of deadly famines under Soviet rule also enormously expanded. This last being made all the worse with many of the soviet-era famines being the result of either deliberate political intervention or sheer economic incompetence coupled with indifference (the 1921 famine after Lenin's war against the white armies, and the brutal Stalinist collectivization campaigns of the early 1930s).

A thorough reading of any number of history books about the economic and political history of the Soviet Union and Tsarism in its last century clearly shows just how much worse so many things became under the communists, and the uglier sides of the Tsarist regime get way too much attention compared to soviet brutalities as "counterexamples" of Tsarism being worse. Even the entrenched nobility repressing a mass of people with few rights was replicated under the Soviet system but, again, just as or possibly even more rigidly through the existence of the ruling "nomenklatura" and their privileges compared to those of your average Soviet majority of workers.

Sure, the Soviet Union dramatically increased literacy rates, it also electrified and massively industrialized the former Tsarist territories that became the USSR but the cost at which this was done in just a few decades literally numbers into the millions of human lives.

On a final quick note, it's also important to distinguish between Soviet communism under the rule of Lenin and Stalin and the nature of Soviet rule after Stalin's death: Political repression, indifference to mass human suffering and the killing of political prisoners all eased up dramatically from Khrushchev onwards, giving the USSR a somewhat more benign image than it really deserved if you consider how brutal life had become in the 3 decades after the Bolsheviks took power from the much more legitimately popular February revolution that had actually taken power from the last Tsar to form a more liberal democratic government.

I can provide a number of good literary sources for the above claims too if you like, just let me know in a response.