Could you point me towards that bit where they blame Brexit?

I can only find the part where it says

> “If this sad decline is not addressed then post-Brexit Britain and the next generation will surely pay the price.”

...which is a fair statement, I'd say.

They might have their cause and effect backwards there.

I can only read, not listen to this, but they aren't blaming Brexit, they just say that post-Brexit Britain will pay the price if they can't figure out a solution, which seems fair. Of course, post-Remain Britain would be in exactly the same circumstance considering the jobs have been going for 10+ years.

The quote doesn't blame Brexit. It's expressing the urgency of the issue and only referencing "post-Brexit Britain," as where Britain stands today.

I believe you are referring to this:

“If this sad decline is not addressed then post-Brexit Britain and the next generation will surely pay the price.”

Or, if the issue isn't addressed, from here on out it will be to our detriment.

That something happens over a long time does not mean that it does not have several causes.

I can remember well how the UK promoted the 'service' and 'finance' industry in the past decades. Manufacturing was seen as obsolete. Especially when North Sea oil brought wealth to to Britain for some time, they were mostly busy managing and consuming this wealth - currently oil is cheaper and North Sea oil is less competitive.