Its because the popular press has, for a very long time, been pushing a narrative of a country under siege. It sells papers, but to keep selling papers, it has to keep steadily upping the narrative over time.
But the UK has always to some extent enjoyed a fantasy of being an island under siege from mainland Europe and it something the nationalist press like to drum up.
As for its increasing poverty, the UK went all-in on neoliberalism since the ‘80s, and especially in on austerity since 2008. Entry-level wages barely grew for over 10 years. Blame the EU for that, get Brexit, more expensive goods and damage to the financial sector the country relied on. Then Covid…