There are two options here.

1. Your project is small enough to not be of any concern to capitalists. You don't claim any valuable resources, and you don't have much industrialization. Your social structure might be great, but you lack the amenities that most modern people would consider essential for a "good life". You could potentially keep this project going for a while within an anarchist framework, but you're not going to change the world.

2. You have abundant resources and adequate industrialization. (Somehow you acquired these without capital or violent revolution?) You are demonstrating an attractive alternative to the capitalist system and are sitting on resources that could be valuable to some major business interests. They WILL try to use state power fucking kill you, if they aren't able to corrupt you and buy you out. You will be gaslighted by every major media outlet, your parents will think you're a baby killing terrorist, and the US military will be preparing an invasion at your border. If you don't adopt a militant, disciplined organizational structure to combat these moves, the commune will be defeated.

That's why, to Marxists, the primary goal is a military victory over capitalism. Of course the socialist states that remain will not represent the end goal, and we shouldn't expect them to "wither away" without effort. But if capitalists can no longer command state power, the viability of the kind of society we want suddenly becomes plausible