Probably the fact that Black Friday is an American phenomenon that is successfully exported to mainly Anglo countries. Doesn't impact mainland Europe as much.
I don't see how Brexit could be part of the reason. Unless the economy is so bad more people are determined to find a bargain.
There's more Black Friday marketing in Britain than some other European countries, and maybe more use of an American credit card based shopping platform.
There should be a something similar to Godwin's law but for any discussion about UK. The longer the thread the more likely someone will mention Brexit.
