There are a lot of reasons for distraction while driving, but we don’t call all of them addiction on that premise. If a driver was not looking at his phone - maybe he’d be looking at something else. The phone is not the reason - it’s just a very suitable object.
[...] the majority of research in the field declares that smartphones are addictive
Though that section continues on to disagree with that majority, "the majority" declaring smartphones are addictive is certainly supportive of them being so.