It depends on what definition of anarchy is used. The philosophical concepts of anarchism are nice, but I fear that the majority only sees anarchism as a situation in wich all rules - no matter if they come from an hierarchy or are collectively agreed upon - are abandoned and the powerful can oppress everybody else and violence is everywhere.One of the core philosophies of anarchism is the idea that I rule no one and no one rules me. Part of criticizing SPEAR comes from that.
That said, the „I rule no one“ is the tricky part of anarchism. It requires a very rigid personal moral codex, the ability to understand long term effects of actions, consequences and a common understanding to make the society better.
In short, in most cases anarchism is a nice utopian ideology that, like so many other nice ideas, fails the moment it gets into contact with more than one human.
To get anarchism to work compromises have to be made, the pure concept gets watered down and you end with a democracy, laws, a hierarchy and all the stuff that is required to get humans to behave in a way that is good for them.
By the way very similar to the „do as thou wilt, it shall be the whole of the law“ from A. Crowley - the tricky part here is to know what you want (really want).
An other nice concept that doesn‘t work are soviet republics. As I said, in the end democracy is the worst concept, but the only on that works.