The sovereignty argument is one I actually have some empathy with. I also think it's one that the majority of leavers - or remainers or non-voters, duh - actually don't care about. The leave vote was essentially a mandate for less immigration, more investment in public services, and no-one to be made poorer for it. As it is, we might get less immigration (to the country's significant disadvantage but hey, it's what people voted for) but good fucking luck with the other two.
The people who care about sovereignty are mainly the people in the Tory party who read about real life in a textbook once. Ask your average leave voter if they care and they might get a tear in their eye and pound their chest triumphantly, but they'd probably change their tune if you said it would cost them, say, £50 a week.
My point is we're basically heading for a Brexit that nobody voted for. The people were asked "Would you like lower levels of immigration, higher levels of public investment and basically nothing else to change?" and answered "Sure, that sounds great." The Brexit elite within the Conservative party has then said, "See? They want their sovereignty back - they don't care if public services get considerably worse or everybody becomes substantially poorer!"