Earlier quoted context omitted.
Brexit was around the same time as COVID, so hard to split the two. >> It's also way higher than it ever was back when Britain was monoracial. Yes, but the immigration model has changed. It used to be "let the best and brightest from around the world work and live in the UK" now it is "let anybody move here that is willing to work for less money".
Well, no, actually. It's not hard to look at the expected effects of brexit and examine whether they are occurring. For example, decline in small forms exporting to Europe due to trades friction. "But the working assumption of the Office for Budget Responsibility (OBR), the government's independent official forecaster, is still that Brexit in the long-term will reduce exports and imports of goods and services by 15%…
You even didn't include the paragraph prior to your quote:
"It's also clear UK services exports - such as advertising and management consulting - have done unexpectedly well since 2021."
I realise Brexit was a horrible shock for the middle classes that they are still coming to terms with, but I think long term it will be neutral or positive. Now that we have a more pro-UK president there is even scope of trade deals with the USA replacing some of the "lost" EU trade.