Why don't we calm down and talk about lesser religions.

Politics is a belief system. Proof (dressed up as incontravertable fact but still mere opinion) can be seen above.

Brexit, love it or hate it is a slow car crash. Predicated on the hope it will be more lucrative but founded on a belief (pick yer pecadillo).

Hard truth is that change costs money. Always has, always will. It costs in unintended (read unthought through) consequences. It costs the losers and there are always some who don't deserve it.

The BREXIT argument (not fact, note) is that the equation results in profits, but in reality only results in prophets. The payback takes time - 10 years suit you? - Sir!
By which time the BRIC countries will loom large and squeeze the profits from the UK (et al). It is happening already.
The goal posts will have moved.

The problem with predicting the future is that it is formulated on past events. Which on a rising curve often works. But we are not on the rise, the ride is bumpy for us right now and if anything overall progress is not necessarily to our advantage as an Emperor once said.