That link is neither analysis nor reporting on outcomes. That's more predictions. This is the exact problem I'm talking about!
To analyze outcomes you must look at the actual data. There's a report that does so here but you can look up the raw data too if you prefer:
https://iea.org.uk/wp-content/uploads/2023/11/Perspectives_5...
From the summary:
"Contrary to initial concerns, Brexit has not had a major detrimental effect on UK–EU trade.
● Trade data doesn’t support the Office for Budget Responsibility’s claims that Brexit has caused significant negative impacts on the UK economy.
● Data from 2019 to 2022 indicates that the trade in both goods and services between the UK and EU hasn’t shown a discernible Brexit effect."
You can look up more recent numbers but the story hasn't changed.
I'd really like to understand the psychology of this phenomenon better. I don't mean this as any personal criticism because it's good that you're asking, but the fact that every time I bring this prediction/reality conflation up I get a rebuttal with more predictions in it is fascinating.