The post 1970s financialization of everything [1] is probably behind most of Britains decline. The UK was just an early adopter [2].
Embracing that nonsense (including rampant neoliberalism) has really rotted the backbone out of our society.
1. https://en.wikipedia.org/wiki/Financialization
2. https://www.researchgate.net/figure/Evolution-of-the-GDP-sha...