That’s another completely misleading and therefore disingenuous stat though.
As it completely ignores the British based businesses that supply goods or services to companies who then produce goods for export. So everything from component manufacturers to IT suppliers, to accountants, solicitors, cleaning contractors, through to the local butty van.
In addition the suggestion that a company that currently doesn’t export to Europe when there’s frictionless trade in place, will somehow magically post Brexit then export to far flung markets around the globe, is fanciful nonsense, backed up by literally nothing.
I'm not sure why you think trading has to stop? Shipping goods under WTO rules and using freight forwarders for the transactions is easy peasy. The processes are already in place.