Britain fell due to the necessity of containing a neighbouring state which have bigger population, better productivity, and the advantage of not having an empire abroad of a continent.
At the end, the Brits fell after pummeling Germany two times.
Both haven't recovered fully today.
So this historical analogue doesn't really speak well to both US and China in the next, say, 3 generations. Wonder who would be the US in this situation though.
https://www.politico.eu/article/china-topples-us-as-eus-top-... China topples US as EU Top trade partner
https://www.upi.com/Defense-News/2019/08/20/Report-Chinas-mi... Report: China's military could overwhelm U.S. forces in Indo-Pacific region
https://news.cgtn.com/news/2020-10-01/From-nobody-to-somebod... China has the worlds largest high speed rail network