Just to make this clear to a lot of people when it comes to Chris Rock's joke - no, comedians don't spend a lot of time and energy evaluation on whether a joke is "Punching down."
People who aren't funny who call themselves "comedians" and get the woke mobs to show up and pretend that they're funny because they're toeing the line talk about "punching down" because they need to push that idea out there in order to protect their careers.
People in the woke mob talk about "punching down" because it's the only way that they can justify using physical violence in response to words and their attempts to silence anybody who dares push anyone's boundaries.
A good joke takes you to a place that you didn't want to go and makes you happy you went there. That means that good comedians, with every joke they tell, they're intentionally taking the audience to a place that they don't want to go and there's always the chance that the audience will bust up laughing and there's a chance that they'll try to kill you.