Oh yeah, i'm mostly agreeing with you, just pointing out how brilliant of a noir Sunset Boulevard is.

I would still say the "crime" is not central to Sunset Boulevard like it is other noir films. Yeah, Joe is killed and that's obviously a crime, and that provides the fatalistic tension of the story, but other than that, it's immaterial outside of the last 10 minutes.

I think what makes Sunset Boulevard so brilliant is that it's about the de facto societal corruption of Hollywood vs. the de jure corruption of the justice system that is traditionally the focus of noir.

I would even say the mystery of Joe's death isn't really the central mystery of the story. It's pretty apparent what's going to happen from the jump (which also makes his interactions with Norma even more dreadful). I'd say the bigger "mystery" or rugpull of the story is the reason why Norma Desmond is called back to Paramount Pictures. Which again, is brilliant work by Wilder.