Curtis doesn't believe you can have a functioning human society without power and he believes that some on the left think you can
that's not a new critique of antiauthoritarian leftism. if anything it's surprising how crude Curtis's version of it is. tho I guess shouldn't be - he's not a leftist himself, isn't familiar with the culture or history the way he is with, say, neoliberalism.
it was a massive - probably the defining - issue for the Spanish anarchist movement up during the Civil War (undoubtedly the high-water mark for formal anarchism in a Western country). the anarchists refused to seize top-down power when they could have because it was completely antithetical to their principles, and to the limited extent that they did it bitterly divided them and the left them in a weakened state for the communist - who had no qualms about brutally seizing power, of course - betrayal shortly thereafter.
it's always going to be a problem for anyone rejecting power, whether they call themselves anarchists or whatever else.
I would point again to the Zapatistas, who have been by revolutionary standards both very successful and always very careful ,through their mouthpiece Marcos to reject the idea of seizing power in a vanguardist sense. not that their organization or society is free of hierarchy, but they've largely escaped that trap of rejecting power/failing to seize it.