When it comes to the global economy, it’s basically true. Only the US and China, and to a lesser extent Europe collectively, really matter - everyone else follows.
US: 25.4T
Europe (well, just EU+UK since I'm lazy): 19.7T
China: 18.0T (<-- totally not cooked numbers)
EU: 16.6T
That's not correct. Also UK is actually still in Europe. Mortal Engines is fiction, not a documentary.
(https://data.worldbank.org/indicator/NY.GDP.MKTP.CD?location...)
(And since someone mentioned California: 3.6T.)