I used to consider myself an anarchist, but considering the lack of success in forming a territory that actually lasts on that method of organization, along with how unlikely it would be to maintain itself amidst a world competing for power, I've come to think hierarchy would be inevitable wherever there are opposing interests or a need for people to adopt roles that involve specialized functions which many others depend on, and seeing that many hierarchies cover vast geographical areas and populations, thus making up states, any movement that aims to dismantle them would either have to evade their jurisdiction or rapidly gain momentum while ensuring it doesn't become what it fights. And even if they're based somewhere out of reach from authorities, that place will either be a mess, a middle of nowhere or both, and so if they haven't already become a cult, there won't be much reason to stick around unless they're in big trouble otherwise, and so if this movement is even going to mean anything they'll of course need to be serious challenge to the state, and that means making potentially divisive decisions, which won't carry much weight if it's just based on some horizontal voluntary participation council or some such arbitrary nonsense that can easily get twisted into mob rule.
If you look at Revolutionary Catalonia or the Ukrainian Free Territory, some of the few supposed examples of anarchism in action, people were drafted to go fight in wars, and political opponents were thrown in prison camps, that is if they weren't just shot.
And I don't say any of this with the idea that there are any state authorities that are truly legitimate, just those that are at best convenient to certain interests.