> There was no free market, thus the USSR was not capitalist.

Of course there was a free market, at least after the NEP was implemented in 1921. Yes there were taxes, but in the USA too, that doesn't make USSR non-capitalist. It's like if you were to say 2022 China is not capitalist for some reasons: yes it has "communist" in the name, and no billionaires are not 100% above the law (contrary to the USA) but there is still money, class, property, gentrification, and everything else that defines capitalism.

https://en.wikipedia.org/wiki/New_Economic_Policy

> I can't believe I'm even arguing this point. It seems like some weird attempt to rewrite history with a narrative "if something went wrong with communism, its capitalisms fault".

Well if you can't believe it, you probably rarely spoke with anarchists. That's the main historical disagreement between anarchists (and anti-authoritarian marxists who are a tiny minority but still exist) and marxist-leninists. The latter claim the "dictatorship of the proletariat" is the road to communism by seizing everything that defines capitalism (State, police, prisons, factories) and placing it under proletarian State governance, while the former consider it's impossible to build communism (freedom and equality for all) with the exploitative tools of capitalism.

I agree with you there's some history rewriting which took place, but it took place about a century ago and it was done by the bolsheviks who erased the memory of the militants who drove the revolution in early 1917 before they seized State power in October and massacred all who disagreed. They were a well-armed minority party who seized State power and applied a dictatorship. They rewrote history and called "counter-revolutionaries" everyone who disagreed, including proper communists who wanted all power to the people. The memories of Emma Goldman, Nestor Makhno, or Volin are really useful to understand the political context of that time, and whatever happened when Lenin and Trotsky (who was chief of the Red Army at that time) had the Communes of Cronstadt and Ukraine massacred in blood.

> No, the USSR collectivized the entire country

That's doubly false. First, social status and private property were never really abolished in the USSR (or rather, were reestablished shortly after being abolished), so you had luxury homes for the cadre of the Party and miserable living conditions for ordinary people. Second, the State nationalized everything, which has nothing to do with collectivization: the Bolsheviks actively repressed the local communities who tried to organize collectivization of land/resources (see also Cronstadt/Makhnovtchina i mentioned earlier).

Maybe give the Emma Goldman link i posted earlier a read? It's really short and you may learn a thing or two about history of that time and place. She's in a unique position because she was an ardent proponent of the 1917 revolution when she was in the USA, but when she was imprisoned and deported from the USA for anti-militarist propaganda, she was confronted with the reality of life under Bolshevik rule and how her anarchist comrades were hunted down by the regime. Her autobiography is a great read, but even the shorter pamphlets are informative.