Also, duckduckgoing it, there are quite a few sources that still claim that the British Empire wasn't profitable for the government in Britain, or regular British people, e.g.:

https://www.jstor.org/stable/2598015

https://iea.org.uk/media/empire-and-slavery-did-not-make-britain-rich-finds-new-iea-book/

(I'm not that knowledgable about the quality of these particular sources, just demonstrating that the claim isn't rare)