GAC as a Bildungsroman...or not

Honestly, I do not see how this is considered a bildungsroman. Neither the main character, Paul Berlin, nor his friends, nor Cacciato, has “come of age” or stepped from childhood into maturity. Cacciato stays the same silly guy throughout the book, with his most dramatic change being the change of living to dead. Oscar becomes more violent and psychotic as the story progresses. Paul Berlin doesn’t really change that much either, except that he gains exposure to the war, gains a better realization of how awful it is, breaks down multiple times in multiple ways, and failing to overcome his fear complex, machine-guns his friend Cacciato to death out of spastic anxiety. Yes, Paul does a lot of thinking and analysis throughout the book, but these segments of the book almost seem forced to me, not like successfully placed drama. For example, the segment of the chapter made up like an imaginary radio show in which Sarkin and Paul discuss indecision, or the segment where Paul asks about fifteen (or more) questions in a row as he thinks of a young Vietnamese girl whom they have administered iodine to, are two of such false-feeling “thought-provoking” parts. There isn’t substantial transformation.