I just can't be bothered to re-fight the old battles. We lost, and we left the EU. I now hope we manage to somehow make the best of it.
The benefits, or more likely negative consequences, of Brexit will only really be able to be judged over the timespan of decades. The world is too complicated to be too sure of anything. It's very likely going to make us poorer as a country in many ways, but hey, we're going to find out for real now. The short-term pain is clearly going to be significant, but probably somewhat masked by the pandemic impact.