Without litigating terminology it is true that there are not like single receptor effects, or that there is a potentially fatal rebound. However it does mess with homeostasis in ways that can make it difficult to stop. Sudden cessation can cause difficult sleeping, anxiety, nightmares, appetite suppression, restlessness, and low mood. It’s relatively easy to deal with compared to stuff that messes with gaba, opiod receptors, or dopamine but it’s still much harder than changing what you eat or whatever.