Earlier quoted context omitted.
The past UK standard of living was based on pillaging the colonies, then after divestment of Empire it was briefly propped up in the 80s by North Sea oil and in the 00s by financial deregulation. No shit we're not going to have the same standard of living as the past.
Colonies were always irrelevant to metropolitan standards of living. See how Norway, Sweden and Denmark with tiny or non-existent empires did as well as Britain, or how Germany and Austria-Hungary were no less wealthy than France. Developing makes a country rich. Looting a non-developed country is a one time thing. Developing is ongoing.
Sweden had an empire, Austria-Hungary was an empire up till the end of WWI. Also, there was extreme poverty in Norway and Sweden not that long ago (the 19th century), leading many to emigrate to the US. The same with German emigration.