What in the world are these people hoping to accomplish?
Semi-serious answer: I guess they kiiiiinda have a point that it's basically impossible to choose to be a non-state citizen, without moving to like, Antarctica/the high seas/the Moon. Living in a state tends to come with obligations towards that state (taxes, expectation of being held to said state's laws), but because nation-states are so prolific and basically cover most of the habitable Earth, you can't really opt out of those obligations.
In practice, the only benefits of being a sovereign citizen would be precisely that - the ability to break laws and duck taxes. (Well, I guess you might feel super empowered or whatever, being sovereign and all.) That said, these people probably still wanna use roads, public courts, hospitals, maybe schools - so it's not like they're prepared to completely opt out of public life.
Seems like they want to enjoy benefits of modern states without contributing to them by paying tax and obeying laws? I wonder if the movement has sincere believers, or if most of them are like the guy here trying to get out of a DUI haha.