The main one I alluded to but didn’t describe in the first message: Marx doesn't talk about workers experiencing alienation from the means of production, he t

The main one I alluded to but didn’t describe in the first message: Marx doesn't talk about workers experiencing alienation from the means of production, he talks about control of the means of production being a means by which the capitalist class establishes working relations which cause the alienation of workers, generally, from the product of their work. Within a broadly capitalist society, though, a worker who does personally own some of the tools of their own trade but continues to work in a wage labor environment is still alienated from the product of their work, though they may have the option to opt out of wage labor, applying their labor to their own capital, avoiding alienation (this is a common pattern of the petit bourgeois, the middle class under capitalism in Marx’s description.) The other is just that Leninism and its descendants (including Maoism) whose results you point to are not “orthodox Marxism”, they are line of variants starting, as the first point of departure, with what was intended as an adaptation to bypass the need for capitalist development as a prerequisite for socialism.