I’m not talking about a utopian communist anarchy, as in absence of a state. I mean anarchy in the sense of societal collapse and devolution.

You do not get sunshine and rainbow anarchy from a state violently and suddenly collapsing. You get massive amounts of death and suffering.

Also you do not get those things under an anarchy. I have yet to hear a sane person explain how communes are going to operate nuclear power plants and massive laboratories to create extremely precise medicine.