Also we really shouldn't be using drug metaphors in general when talking about games.
This and the title seems disingenuous to me. A dopamine rush or hit is not a drug metaphor but a reference to body chemistry in response to something that happens in a game.
Please correct me if I'm wrong
https://www.health.harvard.edu/mind-and-mood/dopamine-the-pathway-to-pleasure
I'm a little confused. I had always read about dopamine as "the reward chemical" like in the link.
I imagine things are more complicated than that like you alluded to but I had always seen it written as a key part of the brain's reward system and so makes sense to mention in the context of rewards in games.