Actual addiction alters mental thinking and results in negative lifestyle effects.

This is prefrontal cortex. It’s dysregulation of neurotransmitters, largely impacted by just how strong the dopamine hit is. Gambling, for example, uses the exact same mechanism as crack to form the neurotransmitter imbalances that lead to people willing to sell their souls for one more hit, and the physical withdrawal is pretty much irrelevant to that impact.

Caffeine is the same thing. It’s less addictive, but it very obviously is addictive by every definition.