As you said, that would be more fitting for a documentary focusing on the creation of the bomb, not a film that serves as a character study of who Oppenheimer is. Nolan made the right choice IMHO to focus on the man over the science, moviegoers generally care far more about the story and characters over details on how things in the story work whether it be fictional or nonfictional. Barely anyone cares that in Lord of the Rings that the limitations of Gandalf’s powers are pretty vague, because they like Gandalf for being an engaging character.
Like, imagine The Social Network focusing more on the details on the programming of Facebook, how people would use the website, etc. as opposed to focusing on who Mark was and how his behavior ultimately alienated everyone away from him (and before someone points it out, I’m aware some of this was changed from what really happened). For me and a lot of people, that would result in a far less interesting film. I’m sure people interested in programming and such would get a kick out of it, but that’s not as wide an audience.
At the end of the day, a subject of any kind, whether it be quantum physics, programming, etc., can only interest so many people. On the other hand, the question of who any person is is universally relatable and engaging. One can’t blame a filmmaker for knowing what most people want from a movie.