New things, new ideas, technology included, tended to upset the existing order of things. You still see that today. There is resistance to change.
Sometimes, the resistance to change led the thinkers and creators to look for a place that gave them more opportunity. That was the New World, and for the Brits of 200 years ago, it was the recently-lost colonies in America, the United States. When it came to technology, another name for it was 'brain drain'.
This is not to say that no talent remained in England and the UK. It took a transplanted Scot, Carnegie, to take the invention of an Englishman, Henry Bessemer, to mainstream the mass-production of steel in the US.
But the culture and the fertile soil for invention were far more conducive to imagination in the US. Britain was too-rooted in the ways things had always been done, This allowed fellow Europeans like the Germans (partly out of the need to rebuild after two great wars) and the Japanese (same reason as Germany) to overtake them in developing new technologies.