There's a good retrospective on the mass protest movements of the 2010s called If We Burn. The main takeaway I got was that leaderlessness and horizonalism do not work.
If you don't pick your leaders, they will pick themselves.
Anarchism can't defend itself. That's the point. Either it gets coopted and recuperated under capital, or it gets hijacked by reactionary forces for their own purposes.
The USSR lost the Cold War, but there's plenty of ML counties still around. I'm sure you'll whine they aren't paradises, but they're all generally progressing and developing in a positive direction (when they aren't being strangled to death like Cuba)
Not a lot of anarchist spaces by comparison. There's the Zapatistas and they're pretty cool, but like, the record is pretty clear.
And before the end of the cold war, USSR was a reactionary country governed by an elite for its own interests. It's the same in China. The same in Vietnam, the same in Cuba (but at least there they have the excuse of the unjust US politics against them).
Eliminating homelessness, eliminating illiteracy, eliminating hunger, increasing life expectancies, increasing graduation rates, increasing quality of life, actually existing socialist countries accomplish incredible things (some more than others, admittedly). They're not perfect utopias, but you can't ignore the context they exist within (i.e. they're still developing countries and they exist within US global hegemony)
I'm sure you have some specific criticisms of China or Cuba or whatever, but they're doing pretty fucking good considering what they're up against.
While you keep on dreaming of utopia, I'm more concerned with defeating than US empire in the real world. Anarchism can't.
USSR “solved” homelessness putting people in prisons and psychiatric hospital… and even then there still was homeless people. Authoritarianism doesn't work.
And Berlin west was a weird political situation, but my argument still holds. People flee DPRK or China…
I mean, anarchism was the initial state, so it has been tried. It seems that it is not very resilient against being replaced by other systems, so it can't really be the best system in the real world.