> everywhere in Britain that's outside of London is now poorer than any given state in the US.

This is true of Europe in general vs the US because economic growth in Europe has been low compared to the US since at least the financial crisis. At the time GDP of the Eurozone was comparable to the US' now the US is almost twice as big. As a consequence every European country ranks low compared to US states on GDP per capita:

"Italy is just ahead of Mississippi, the poorest of the 50 states, while France is between Idaho and Arkansas, respectively 48th and 49th. Germany doesn't save face: It lies between Oklahoma and Maine (38th and 39th)." (2023) [1]

[1] https://www.lemonde.fr/en/opinion/article/2023/09/04/the-gdp...

> At the time GDP of the Eurozone was comparable to the US' now the US is almost twice as big

No, You're just comparing change in the EUR/USD exchange rate here. In 2007, the euro was at a high point of 1.48, and in 2024 it's at a low of 1.02. Inflation has not been higher in Europe than in the USA over that period.

If we look at GDP at purchasing power parity from 2007 to 2023 we have this:

- European Union: 31,162 → 61,217, +96% (https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD?locat...)

- USA: 48,050 → 82,769, +72% (https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD?locat...)

Which shows a slight catching-up by the European Union over the period.