Direct democracy is authoritarian

Yes, a valid point, and I actually agree. It's rule of the masses. But it's a much different thing than top down authority. It's the polar opposite of the Marxist model that embraces top-down authoritarianism, because this type of authority is by dictate. I'd say it attempts to be anti-authoritarian by distributing the authority among many instead of a few, but ignores tyranny of the masses.

I'd consider this anti-authoritarian, because the aim is clearly to eliminate arbitrary dictates and reduce the power and authority of any individual. But I would also say this doesn't work as intended, and we end up with a different sort of tyranny that is not any better, or less authoritarian, just different

Both mobs and despots can be tyrannical