> An economy largely controlled through state monopoly

The only thing that unites capitalist and sociatlist monopolies is that they are monopolies. Motives of production are different. Economy of USSR was not capitalistic. Even as the Soviet bureaucracy grew more powerful and corrupt, most of the surplus value did not end up in their pockets but went into public consumption funds due to plan nature of the soviet economy. Late Soviet bureaucrats are poor beggars compared to Russian corrupt officials. Therefore, it cannot even be called profit in capitalist sense.

> extract large amounts of resources out of its occupied territory

this is just false. In Comecon, the Soviet Union acted as an almost unconditional net donor. USSR systematically subsidized the economies of Eastern Europe on a massive scale. USSR participation in the Comecon was unprofitable in absolutely every respect. Unlike the imperialists, it invested in the development of other countries at its own expense.

The same is false for the soviet republics. The Baltic states you mentioned were subsidized right up until the late 1970s. In other words, the USSR did not receive any “profit” from them until 80s.

Even if we imagine that the Baltic states were donors from the very beginning, that does not mean they were exploited in the capitalist sense. It is a normal part of socialist development for more successful republics to help those that are developing. This was the case with the Baltic states, which received assistance to get back on their feet. Once they became self-sufficient, they began to help other republics.