Humans tend to want a "hero/villain" in our stories. Irl, thousands of people worked on the Manhattan Project and even more had done the theoretical work before it. E.g., a lot of work done by the Brits on the bomb are forgotten because it was the US who built it first.
Oppenheimer Movie
A community dedicated to Christopher Nolan's thriller Oppenheimer. The movie is now playing in theatres.
Oppenheimer is an upcoming biographical thriller film written, produced, and directed by Christopher Nolan, based on the 2005 book American Prometheus by Kai Bird and Martin J. Sherwin, about J. Robert Oppenheimer, the theoretical physicist who helped develop the first nuclear weapons. The film stars Cillian Murphy as the title character, with a supporting ensemble cast including Emily Blunt, Matt Damon, Robert Downey Jr., Florence Pugh, Josh Hartnett, Casey Affleck, Rami Malek, and Kenneth Branagh.
Yes, you are right - a lot of people worked behind the development of the nuclear bomb. I don't know about the Brits, I gotta do more research that.