I love Scorsese and I usually don't mind how long his films are, case in point Killers of the Flower Moon. But Gangs of New York is not only too long and weirdly self indulgent, but whatever Cameron Diaz is doing in her role is... Not great and makes me sad every time.
Edit: I realize I inverted flowers and killer in Killers of the Flower Moon.
That movie has so much interesting history stuff like the gangs controlling the fire brigades and the city being rebuilt time and again but it's at odds with the weird cartoon vibe of the characters and story.