Er... that chart shows the UK GDP per capita about on par with France's (even slightly higher) until 2018, and from then on it has been consistently below France - not by a lot, but still noticeable...
A tiny difference and the big difference was that the UK fell back more during covid in 2020. the difference fluctuates from year to year it was only $300 (a 0.5% difference) in 2022.
https://ourworldindata.org/grapher/gdp-per-capita-worldbank?...
Only Italy has done substantially better, but that is recovery from the aftermath of the 2008 collapse.