The argument that Marxist-Leninism and Marxist-Leninist-Maoism are the only valid ideologies because they are the only ones that held on to state power is essentially an appeal to past and present hegemony. This is eerily similar to an appeal to Capitalist Realism—that there is no alternative.
Just as we must push back against neoliberal capitalist ideology that incessantly tells us “there is no alternative,” we must be sceptical of ideologies that suggest theirs is the only way.
Neoliberalism isn’t very different from the CCP ideology. Don’t forget China has more billionaires than any nation on Earth.