Oh yeah, Anarchists.
The people who still live in the Impossible times. It's worse than utopia.
No, what you get with Anarchy is Somalia. Sure, anarchists say "that's not really anarchism" the same way communists say "North Korea and every so-called communist state isn't really communism". Yet, Somalia embodies each and every aspect anarchists want to implement. It's the conclusion of the principles.
No overreaching legitimate authority leads to the rule of the strong or the mob. The abscence of large-scale contractual obligations and means to enforce them leads to tribalism and/or indentured servitude. Since there's no rules forcing people to do anything, the only means to ensure anything gets done at all is social pressure, like in the olden times, with the "credit economy". Vendettas. Nepotism. Clientelism.
Nothing big gets done, because that would require either a central direction (forbidden!) or the common and unwavering agreement of a large quantity of people, when public opinion changes like the wind.
No fundamental research, because no individual has the means to conduct it and no individual wants to waste funds in it (it's investements you won't see back in your lifetime!).
No united front against any external threat, so extreme vulnerability against anything, from invading foreign countries to cults to pyramid schemes.
Anarchy can't work. It's not even like fascism which is just inefficient and morally dubious, no. Anarchy can not possibly work, not in a scale above "isolated hamlet or internet community".
It's even funny to see that in each and every pseudo-anarchist internet groups, there are driving individuals. Leaders. A hierarchy, and rules, and authority, because nothing is written, it's all social drama. Hilarious.