This isn’t actually true. AES states are Socialist, the concept of “State Capitalism” refered more to the NEP period. Communism is always meant to be based on Public Ownership and Central Planning, because Marx observed Capitalism’s natural tendencies to centralize and develop intricate internal planning mechanisms.

The essential condition for the existence, and for the sway of the bourgeois class, is the formation and augmentation of capital; the condition for capital is wage-labour. Wage-labour rests exclusively on competition between the labourers. The advance of industry, whose involuntary promoter is the bourgeoisie, replaces the isolation of the labourers, due to competition, by their revolutionary combination, due to association. The development of Modern Industry, therefore, cuts from under its feet the very foundation on which the bourgeoisie produces and appropriates products. What the bourgeoisie, therefore, produces, above all, are its own grave-diggers. Its fall and the victory of the proletariat are equally inevitable.

Regardless of your opinions on the successes or failures of AES, they were and are very much in line with the Marxist notion of Socialism.