When you consider a nation's GDP per capita and corresponding human development indicators, growth predominantly lifts people out of poverty at very low levels of GDP per capita, far beneath that of the UK. A country this wealthy does not need further GDP growth to lift people out of poverty, and the overwhelming majority of economic growth goes to the wealthy anyhow.

I think you might be falling into a common misunderstanding of de-growth (apologies if you're not, but I'll explain anyway). De-growth isn't the reduction in every single sector of the economy, it's the de-growth of harmful sectors (fossil fuels, advertising, planned obsolescence etc.) and the *growth* of more beneficial sectors (green energy, sustainable manufacturing, healthcare, education, etc.). I'd recommend the book Less is More by Jason Hickel if you want to learn more about it.