There are a number of factors at play including delayed testing because of covid, relatively low wages, and perhaps drivers shifting to more local deliveries e.g. supermarkets post covid due to changing demand. I was speaking to a taxi driver who said the taxi industry was being decimated by this
Yes, though Europe is a larger "network." I think it's a bit like Metcalfe's law. Even if the EU has similar shortages of labor or goods, the larger number of citizens and companies allows things to flow to and from wherever they're needed more easily. The UK is now a separate far smaller system no longer plugged into that larger network.
Those are Human beings that have to be, in essence, "stolen away" from another job, in the case of high school graduates (or whatever you call them) from another potential career. That's why wage isn't the magic wand many people believe it to be. If one industry increases wages (provided they can afford it), another gets the short stick. Unless you "steal" workers from other countries. As the UK did/does successfully for example with health workers...
So yes, while there is a wider issue, the wider issue is not the current problem or the high-order bit.
Note also that UGKOV plans to address the driver shortage by offering to ease restrictions on non UK-based (i.e. EU) drivers.
So yes, this is totally due to Brexit.
Hard to imagine why they might not be jumping at the chance to spend another Xmas with no access to sanitation or even food in a place that is run by people who abuse them publicly every day