It's also worth considering that the UK economy in 2021 is larger than it was during WW2, so a small percentage impact in the present day would be a bigger absolute value than the same percentage applied to the past economy.
Re:UK to depart from GDPR
by callamdelaney on Friday March 12, 2021 @07:08AM
(#26434887)
Those statistics were later revised by the Bank of England, after the damage was done obviously, so I guess you're wrong.
But on your WW2 point, I did think about it for a minute.
Britain fought WW2 for 6 years, 1939 – 1945. Brexit has no known endpoint. Imagine that even 10% of the trade impacts we've seen since the end of the transition period on 1 January persist. Then you can quite easily calculate how many years it will take to damage the economy more than WW2. Off the top of my head, I don't know if that's 6 years, or 60 years, or 600 years. But there's certainly some finite number that will do it.