I think you will see urban decay now anywhere you go, and if you think about it, it isn't Brexit, Stupid Govt's, its that people have changed their habits, Online shopping, cheap booze in supermarkets, take away food and delivered meals, people are now in the habit of staying in, and they have in some cases seen how much money they can save, down here in Cornwall where i live, I see 10 -12 ASDA, Tesco, et al, vans delivering the groceries to the houses around me every day. I can buy a pint of lager in a can from Asda for about £1.20, or i can go to a Pub and pay upwards of £4, luckily I don't drink, but I can understand people drinking at home. Also the smoking ban has had an effect, especially on pub traffic.
It is a shame really to see the local high streets die, but they are mainly Charity shops, Phone shops, pound shops, coffee shops, and I think they have now seen their days, out of town shopping another nail in the coffin, high car parking charges in the town centres, etc, it's a new way of living, and some of the things we relied on are now gone, even attitudes to shoppers have changed, very few litter bins in our Town Centres now, probably cheaper to employ a cleaner now, because of the low footfall.