They are not legit in the sense that they are well-defended against the governments (although Liberland is in principle outside the territory of any nation, it's still attacked). We can't compete with the governments in firepower.

That doesn't mean that concentrating on the government territories is useless. In US that doesn't work because the Feds intervene (see the fate of Ian Freeman). But small countries might not have enough resources to crack down on a large group. See for example https://montelibero.org although they're shitcoiners big time.