It implies a direct connection with neurochemistry that's much less direct than drugs (and even moreso diet), which can directly stimulate the release of dopamine. For example if I'm feeling tired of scrolling through memes, I can just put my phone away. I can't stop caffeine from stimulating my neurons, or ignore a macronutrient deficiency in my body.

It might be that this is an unimportant distinction in the end, but I'm not sure we know.