Wouldn't this be consistent with social media being easier to quit than both junk food _and_ cigarettes? Given that, I'm not sure how can conclude which of them is more similar.

As an alternative take, my understanding of the difference between cigarettes and junk food is that cigarettes are more physically addictive than junk food (which at least to my naive medical understanding is more of a "psychologically addictive" substance than something that the body will literally start to reach poorly to withholding after repeated intake). I haven't heard of anyone ever suffering physical withdrawal symptoms from having to wean off of either junk food or social media, which makes them seem much more similar to me than either are to cigarettes.

As an alternative to either of the headline options, maybe it would make sense to compare it to alcohol? Unlike cigarettes, most people are not physically addicted to it when using, but unlike junk food, you still shouldn't be using it when driving.