> mostly from sci-fi which has always been a breeding ground for these things
That's cool! But if you want to do some more reading on actual anarchism, i would recommend for example to read about the zapatistas in today's Chiapas, or the spanish revolution, or the ukraine commune. Or maybe read on the history of anarcho-syndicalism in your area, for example the history of the IWW in north-america.
Anarchism takes many forms across the places and ages. Some people even make connections in their anarchism to much older ideologies such as christianity or taoism (among others). I personally find it important to recognize that anarchism is not a single ideology but an axiom (abolishing authority) with which to build specific political frameworks. In that sense, it's a very rich and diverse body of thought that's worth exploring in my view.
> [i am not convinced that] the important capabilities an entity must have (ie territorial defence) are capable at the scale you’re talking.
I believe it is. The antifascist militias in revolutionary spain in the 1930s and the Makhnovshchina in Ukraine in the 1910s are good examples. They both were crushed due to being heavily outnumbered and outgunned. Franco's army was heavily supported by both Hitler and Mussolini. The peasant's self-organized army in Ukraine had been successful at defending territories from both German troops (WWI) and the white army (royalists supporting the ousted tsar).. it's only after being weakened by all that, that the Red Army led by Trotsky was successful in betraying (they had an alliance) and defeating them.
> You can see how A potential collapse of the US could lead to these sorts of groups (ie well armed local communities).
I may be naive, but i personally think well-armed local communities cooperating for mutual interest is a much better situation than the current generalized injustice we live in where local populations are mostly powerless against State-backed industrial projects to expropriate them from their land or pollute their territories. I'm happy to elaborate on that topic (ZADs, forret occupations, etc) if you will.
> Things could be significantly better if the cowards in power made better decisions
I personally think things would be better if there was no people in charge. Without a centralized police apparatus to arrest/imprison people, there would be zero homeless, given that there's an abundance of empty dwellings and that the vast majority of the population supports fighting homelessness (instead of fighting the homeless as our governments are doing). If there was no police and no State apparatus, we could almost literally snap fingers and have everyone housed: well that's a metaphor of course we'd need drills or lockpicks ;)
> such a stunningly large number of people compared to all of human history now have education, electricity, food, shelter
I think this is a very reductionist and dangerous argument. I'm not arguing that the past was a golden age of happiness and leisure, but there's certainly countless metrics that have significantly worsened over the years, as well as an unmeasurable "quality of life" that's also worsened.
We could for example mention free time (peasants from the middle ages had a lot more of that), clean environment (1/3 of the world population now drinks lead, and there's a lot more pollution sources than lead), as well as environmental changes (desertification) due to industry and monoculture. Just because some communities are/were poor in a materialist understanding of the world does not mean they have a poor/unhappy life.
I understand that the argument for "progress" is appealing, but i personally believe it does not stand scrutiny. There's a lot of great advances (for example in medicine) that i wouldn't want to live without, but there's also many social/technological developments that i personally believe to be entirely hostile to humanity and countless other species not threatened by what some people refer to as "capitalocene".
My point that we live in the worst timeline does not imply that everything is going bad, but rather that for some measure of some things going good, there's countless other things going really bad, bad enough to threaten a new massive extinction of species. How is that not the worst timeline? ;)