I think that’s always the way. Compartmentalisation. Though I don’t blame the film for not showing the horrors taking place in those cities. At the time Oppenheimer wouldn’t have access to those images, and so I guess neither do we. On the other hand - unless I miss remember - we do get to see him watching a film reel. So, maybe they could have shoehorned the scenes of destruction. But, personally, I think it’s enough to see the effect it has on Oppenheimer. Any more could be classed as prurient voyeurism.