That would usually be a fair point, except you missed the point where USSR economic growth also beat the growth rates of less or comparably developed countries that were not communist, e.g. the Southern American countries turned capitalist under US influence.

So a point in favor of communism remains.

In any case, the true lesson is probably that communism vs. capitalism just doesn't matter as much as people want you to believe. Other factors -- such as whether institutions are inclusive (targeting the welfare of the entire population) or exploitative (transferring wealth towards a small elite) -- simply matter more.