There isn’t much demonstrated success applying this in practice however.

There is and there was. That most anarchist communes have been eradicated by authoritarians of all stripes doesn’t mean they weren’t successful. The two last ones to fall in the past few years, la ZAD and Exarchia, were really amazing communities where one could live without money and (mostly) without oppression.

they were still very much under state control

It depends. State control was widely limited by (lack of) technological means. People living in the mountains/swamps were mostly rid of State control because there was no gasoline to take an army up there. And whatever control the State had, they didn’t have cameras on the streets and a television spitting lies in every home to exert their control.

I’m not idealizing the middle ages, there were a lot of problems. But free communes and peasant uprisings were a thing back then. Can we say the same today in the western world?

Feudalism wasn’t any closer to anarchism than capitalism.

Definitely not. My point was simply that back then, people could technically evade feudalism by fleeing from the centers of power. While evading capitalism today is mostly impossible (or please show me how).

Perhaps Zapatista would be the closest example, although they don’t consider themselves anarchist. Yet, even they only managed to carve out a niche for themselves within of a capitalist state.

From my (limited) understanding of the zapatistas, they are indeed an anarchist movement (from my definition). They are building dual power from the ground up without higher authority.

What really sets zapatism apart from other marxist revolutions, is that the armed branch of the revolution (EZLN) explicitly recognizes they are not representative of the people and the people should decide for themselves. EZLN is only here to protect the revolution against outside threats, and does not worry about internal politics.

This healthy self-criticism and strong separation of powers is what enables the movement to build concrete autonomy, whereas revolutionary avant-garde (of the past) have actively sabotaged revolutionary efforts (eg. bolsheviks taking power away from the soviets, into the hands of the State).

Also it’s not a small niche. Zapatist communities are huge, and are well connected to the social struggles of the urban centers. As recently as last year, the movement announced the creation of new autonomous regions (caracols) so it’s still growing.

there have been numerous successful ML revolutions that liberated millions of people across the globe

And killed/enslaved millions of others. “Liberation” is not how people in the USSR/Spain/China experienced it: see Cronstadt/Makhnovtchina for example of true revolutionaries rising up against the counter-revolutionary bolshevik tyrants for social justice and self-determination (spoiler: they were massacred). If you’re interested in that, Emma Goldman has very detailed, first-hand accounts of her disillusions with the Russian revolution and the bolshevik dictatorship (of the proletariat, or so they say).

The first question that needs to be asked is how such a system can be overthrown in order for something different to be possible.

For me the first question is how can we avoid reproducing this, personally and as communities. Overthrowing a system of oppression to replace it with another one is of no interest to me. Whether i’m placed in a concentration camp by the capital’s police or the people’s police makes no difference to me. Burn all prisons and police stations, then we can start to think differently about living together as a society.