I’d say that those “extremists” are more likely people who are young (either biologically or in exposure to anarchic philosophy) and a bit naïve. They may have their heart in the right place from the perspective of those of us who have been about for a while but, likely are lacking in real-world experience with anarchic social circles and challenges that they have (wreckers, narcissists, cliques, etc).
What you’re mentioning is more of the shallow view of anarchism that’s most frequently portrayed as the alternative to the other popular Mad Max view that right-of-center groups like to use to portray “anarchy”. Neither are great at showing the full gamut of anarchic philosophy nor particularly accurate portrayals of extant or historical approaches to non-hierarchical societies.