Brexit long since ceased to be about perceived benefits for the public because er, there aren't any. All their guff about trade opportunities has been totally debunked and even Man of the People Nige doesn't bang on about immigration as much now, as a) we need immigration to make our economy work and b) pretty clear that non-EU immigration will just replace EU immigration, if anything. Bollocks about say, fishing is just inane drivel and even when challenged Brexiteers can't name specific EU laws (which we helped draft and pass, remember) that they'd like to repeal.
So now, the public argument is that we have to do Brexit because we had a vote once. Doesn't matter if any number of votes since indicate that it's not a very good idea and people don't want it, or how flawed said vote was, or how badly the period since has gone, or how bad the projections are, or how little of a plan we have. We just have to do it apparently or the country will collapse into the North Sea. In private of course it's about enriching already wealthy people and always has been.
The exception to this being Jeremy Corbyn who thinks if we leave the EU it'll be 1983 again and he can run the country as he would have done then.