There are examples of libeterian socialist societies today (chiapas, rojava) and historically (spain, ukraine etc.). What's common with both is that they have to put up with relentless attacks from capitalists and fascists. Yet despite that they, in the case of rojava and chiapas, have prevailed.

If you think anarchism can only work in small communities then there are anarchist theories focusing on smaller communities, like Bookchin.

Revolution also isn't something that happens in a day and suddenly you have to re-strucure all of society. During and before the revolution you are already creating these anarchist structures so when you get to that point you are prepared. Working with mutual aid for example doesn't just help people now but train ourselves to live a different life based on solidarity. I believe that even if anarchism will never happen it still worth pursuing these different forms of organisation. This is partly because I am fairly confident capitalism, at least globally, will collapse. Climate change among other things will see to that. What will come after might truly be horrific but I believe anarchism is going to be the only real alternative to it if we want to live truly free.