Yes, (most) everything is feasible in smaller populations (not nuclear maintenance for example). But without technology, they've been isolated, uncoordinated, and easily bullied by those larger organized authoritarian bodies. There are billions of people, and narcissists make up about 1 in 5 of those billions of people. A smaller subset lack basic empathy, and an even smaller subset are intellectually competent. Multiply whatever that probability is by billions of people, and you have a guaranteed concern for every single government on the planet.

I agree with wanting smaller businesses as well. Capitalism isn't bad (communism is state capitalism after all), but corporatism is the emerging problem from right libertarianism that most people conflate as problems with capitalism

My point being isn't that I don't like leftism, they are my ideals. I just don't believe we live in an ideal world, so practically I follow a different set of beliefs. Thay said, I do think leftism is compatible with libertarianism in a way that it can compete in the global arena. And that starts off with solving how a decentralized governmental body "identifies" one and only one person to their "identity" (otherwise you get Sybil attacks)