Re: So, to sum up. . .
"The purpose of Brexit is to restore sovereignty to the UK."
Purpose and result are two different things. As an isolated nation the UK will have far less clout in the world than it did as part of a larger block. (Note that phrase "part of" because that's the situation, not "subject to" which seems to be the Leaver view.) I really can't see how having less clout equates to "restored sovereignty" but, hey, we'll have taken back control.