I have not seen the film yet, but it seems like this is a biopic about Oppenheimer, not a WWII movie.

Also, do directors need to infantilize their audience by directly showing "this was bad. Here is why this was bad"? Like, obviously the bombings of Hiroshima and Nagasaki were devastating. If you have basic history knowledge you should already know that, and know that those bombings were a direct consequence from what was depicted in the movie with out it being spelled out for you.