But there's no referendum on that. My main point is that the referendum wasn't very sensible and should probably always have had two stages. X = "What kind of Brexit do we want" then "remain vs. X". I expect "hard Brexit" vs. remain would have gone the other way, for example.

And the way to rectify this is to have a referendum on the reality of the eventual deal vs. the reality of the status quo.

GB existed before the EU and will continue to exist after it.

Nobody thinks otherwise, but “the country will continue to exist” is a pretty low bar to achieve. I’m much more concerned about a massive spike in prices, people leaving the country, and difficulty importing and exporting goods.