have you lived in a former/current communist country? from firsthand experience, it's a mixed bag. some communist, some simply not supporting it, and some actively against it. labelling anti-communism as inherently fascism (when, the nuance is more-so that fascism often inherently INCLUDES anti-communism but anti-communism isn't inherently fascist) invalidates the millions of people who were harmed under communist systems. theory doesn't always fit neatly with human factors
i have, though again, not a monolith. just lived experience. fascism is threatened by communist ideology but again, anti-communism itself isn't inherently fascist. a lot of anti-fascist movements in history were also anti-communist (spanish anarchists, prague spring, polish solidarity movement etc) and even currently movements in tibet and hong kong. treating it as interchangeable flattens the experience of workers who were harmed by the very institutions who claim to protect them (familiar)