//Any suggestions how they were supposed to do that?//
In the same way as businesses react to any other potential threat – by making plans to deal with it. It’s for directors and managers to manage those threats. There was five years notice that Brexit was going to happen. It didn’t creep up by surprise. Many businesses spent too much time wailing about how they would be unable to cope instead of devising ways how they could. Many politicians exacerbated this mood by continually suggesting that either Brexit would not happen (and doing their best to make sure it didn’t) or suggesting that the UK would remain as some sort of vassal state or “associate member.” Businesses should have ignored these politicians (as they should whenever making their plans) and planned for a proper exit from the EU.
There are always different views. Here’s a couple of papers (from the same source) which support mine. They are both quite in depth so I’ve only replicated the conclusions. But they are worth a read if you want to examine the issues properly rather than simply repeat mantra.
Firstly, one which concludes that the UK’s membership of the EU did not particularly help the country’s economic growth (dated 2nd November 2022):
https://www.briefingsforbritain.co.uk/eu-membership-did-not-accelerate-economic-growth-in-the-uk/
“We can conclude that there is no evidence that joining the EU improved the rate of economic growth in the UK. Growth in the UK, as elsewhere, is constrained by technology, skills and investment. None of these have been better than the USA and hence the USA experience puts a ceiling on potential long-term growth in the UK, as it does in the EU6. The irony is that the UK joined the EEC just as the EU6 catch-up was ending. The UK thus joined on a false prospectus that accession would accelerate growth. Also ironic is the fact that the previously slow growing Commonwealth markets have actually expanded faster than the EU over the long period since 1973. If the performance of the EU had been better, and the Commonwealth worse, the UK may have felt less temptation to leave, but this was not the case."
Now one which concludes that Brexit has not done much harm to the economy (13th October 2022):
https://www.briefingsforbritain.co.uk/what-impact-is-brexit-having-on-the-uk-economy/
“Eighteen months after the UK left the EU customs union and single market, apocalyptic predictions about the negative impact of Brexit have proved illusory. Nevertheless, there have been many attempts to show that Brexit is damaging, or has damaged, the UK economy. These attempts are based on flawed analyses, often featuring tortuous attempts to twist the available data to fit a pre-conceived anti-Brexit narrative.
A careful reading of the evidence shows that while there is little evidence yet that Brexit is doing much to help the UK economy, neither is there evidence of much harm. This is significant because it was generally agreed, even by Brexiteers, that there would be initial difficulties.”
Of course you can tear these opinions apart, but they do provide evidence that the notion that Brexit has been “disastrous” cannot be unconditionally stated as if it was fact. Yes, some businesses and individuals have experienced some difficulties. But that was always going to be so. But overall, “disastrous” is not an appropriate description.
The first report is equally interesting. It has always been somewhat a “given” that the EU was good for the UK economically (and hence Brexit was bad). This is also debunked.