I agree.
The violence in Joker is more personal and visceral. Especially when he kills the fellow clown in revenge, in his own apartment. I found that far more shocking and affecting. The production and acting causes you to experience the fear, and violent outburst of rage.
But it is not more violent than most PG-13 fare.
Right, the apartment scene is very visceral even though the camera manages to keep the absolute brunt of it out of frame. It feels like it’s happening right there next you and you can imagine what it must look like. This is why Joker is R rated while True Grit isn’t — because intensity and realism matter. In True Grit the headshot is stylized and quick. In Joker there’s more splatter, more realism, and the camera lingers longer on the aftermath. Quantifying violence is kind of like defining pornography: hard to pin down but you know it when you see it. To me it’s more or less self evident that the violence in Joker is the R rated kind.