One of the things that has increasingly bothered me about games is...

Level Up, XP Gains, loot, achievements, new skin unlocks, daily rewards... basically just numbers go up.
Dopamine is an important part of what makes games fun. It drives motivation, learning, anticipation and so on.
But I think the real win is making players long-term happy instead of giving them short-term kicks and then just making them jonesin' for more.
I think people don't just want rewards, they want attachment, relationships, connection. They want to feel that they've accomplished something meaningful. They want to care about characters and worlds. They want to belong somewhere.
We basically all want memories that stick with us.
That's where things like social connection, attachment and hormones such as oxytocin become interesting.
My point is: I think oxytocin is what we should be focusing a lot more on than just providing dopamine kicks. Oxytocin isn't some magical happiness chemical, but focusing on that points devs towards a fundamentally different category of experience than simply rewarding the player again and again.
Instead of just focusing on how we keep the player engaged for another 10 minutes, we should focus on how we make the player genuinely happy that they spent 100 hours with us.
And those are very different design problems. I'd say a dopamine-oriented game might make you constantly want the next thing, it's eerily similar to drug-seeking behavior.
But a deeply satisfying game might make you think about the things you've already experienced in life.
I know that talking about games in terms of neurotransmitters can sound fucking weird, but I actually think it's useful to sometimes strip game design down to the underlying human experience.
We're ultimately building systems that create experiences inside people's brains. And because of that, we ought to treat players brains with care and respect.
I'd always wanna make the kinda games that I'd be proud to have my kids play instead of games that are purely focused on making players want / spend more.