There was a lot of over-the-top commentary on both sides. The reality is that “we don’t know what will happen”. If you do, then buy and sell shares, and be rich!
IMO - it’s a long term negative. E.g. my friend used to work at a US company European HQ in London. He doesn’t any more...
Also, the EU never stopped The UK selling to Asia, so why is that used as “the future”?