(epistemic status: I’m an incrementalist. That means I support doing small things in the direction of this and checking whether they work.)
Archipelagoism, the political philosophy of lots of self-governed states which can operate by any rule at all as long as they have unconditional exit rights. So if someone wants to live in a feudal monarchy, they totally can – but anyone who doesn’t like it will leave, so good luck oppressing your inferiors. Want to set up a fundamentalist religious state? Okay, but I can set up a state specifically for ex-members of your fundamentalist religion who want to stop following your strict laws, and anyone who is unhappy in your state can come to mine.
You really really like revolution? You can have a state that overthrows its political system every few years, but if it sucks (and honestly, sounds like it’d suck) then no one will choose to live there and it’ll die out.
You want a communist state? You have one! And if it works everyone will join you and we’ll have full communism. But anyone who isn’t happy has the right to choose a different system.
The way to make this work is probably to separate governance from control of physical territory. A government is a contract between all of the people who agree to abide by the government’s system for choosing laws and the laws themselves, in exchange for whatever benefits the government offers them. Governance will probably mostly be local because it works best locally, but you needn’t claim a bunch of territory before you can start calling yourself a government. This makes it easier for people to leave, too, since leaving needn’t involve uprooting yourself to somewhere where you may not speak the language.
As much as I’m in favor of this in most cases, I still have yet to be convinced that it does an adequate job of protecting the rights of children and animals. In the case of children you can say that they’re allowed to leave whenever they want, but brainwashing is a powerful tool, and some kids are too young to even communicate their desire to leave. If someone decides that they want to have a nation where they beat their infants and just let them die of preventable, deadly, and-or permanent disability-inducing illness, should they be allowed to? And once you start regulating what kids can be exposed to you start going down a long road of banning things that might conceivably harm young children.
The question, then, is this: Does our current system do an adequate job?
To which I feel the answer is not obvious.