I’m willing to agree partially: AFAIK the usual classification of the economic system of the SU is “state capitalism” which is indeed distinct from capitalism and socialism and I’m even willing to grant it that, if well executed (in the SU it mostly wasn’t) it has the potential to be better than capitalism in a few aspects.

That said, I agree about the notion that fascism is a form of capitalism: The two are often associated with each other, but at the end of the day quite distinct and orthogoanl systems. Fascism is about having a powerful leader who oppresses the population and the SU very much had that in an almost textbook-manner with Stalin, though I will also acknowledge that there were of course detals in hwo it differed from say Naziism in Germany at the same time.