The best explanation (ever) for a sovereign citizen is found in a legal opinion by a Canadian judge. He spends about 176 pages delineating their beliefs, origins, and manner of interacting with the legal system.
https://www.canlii.org/en/ab/abqb/doc/2012/2012abqb571/2012abqb571.html
Aye, anecdotally, there was a school near my childhood home, other side of the street and about .8 miles away. The line of cars used to be about halfway to my house. Now, when I visit family, I see it stretching past my house and it at least stretches a full mile in length now. It’s nuts.