I wish people didn't overuse certain terms. Dopamine has a half life of 2 minutes in the body. It can't possibly keep you up at night.
It's just the caffeine, which in turn has a half-life of several hours. Also below a certain level it's eliminated approximately exponentially, so there's a long tail of residual caffeine.
May be true.
But doing "rewarding" work encourages your body to emit more dopamine. Some people call it "the flow", others "hyperfocus", but it is a constant stream of dopamine that keeps you doing what you currently do. And you can interfere with the emittance and absorbtion by using caffeine.
Fair enough if the use of “dopamine” is imprecise, but excessive screen time / doomscrolling / shitposting is definitely enough to wire you awake on its own, without caffeine.
That's for IV dopamine, used in extreme circumstances. Natural dopamine lasts shorter than that!