I agree that it would be misleading to maintain that most of us are addicted to our smartphones. My favorite definition of addiction is "a progressive narrowing of the things that bring you pleasure" (source: episode 33 of the Huberman Lab podcast: https://podcastnotes.org/huberman-lab/episode-33-dr-anna-lem...) caused by an all-encompassing involvement with a substance or activity. Most of us do not have an all-encompassing involvement with our smartphone that is gradually removing or has gradually removed our ability to take pleasure in anything other than our smartphone.

But smartphones and social media share with addiction a nasty adverse effect: they sap our motivation for weeks after we indulge in them. Pleasure and motivation are intricately connected in the human mental architecture, and it turns out that pleasures that can be accessed easily and without effort tend to sap our motivation (again, for weeks after the pleasurable experience).

Older technologies like television have the same problem, but most of us are smart enough not to start watching television till later in the day, after we've accomplished something that took effort, and probably hours of sustained effort. The big difference between TV and the web or a smartphone is that the web and the smartphone have many practical, productive uses, which gets us to use them early in the day, perhaps just after waking up, but while we are using them we are always only a few clicks or taps away from a diverse range of pleasures that can be had without effort (or with just a slight amount of effort, e. g., reading 10 or 20 headlines on HN that you are not interested in before finding one that gratifies your sense of curiosity) and of course the fact that they're pleasurable cause us to learn to make those few clicks or taps without even thinking about it.

"The problem is not pleasures. The problem is that pleasures experienced without prior requirement for pursuit is terrible for us." (Source: neuroscientist Andrew Huberman in https://www.youtube.com/watch?v=jBwM-mCLQQo)

In conclusion, it is natural for the average person to reach for the word "addictive" when describing social media and smartphones. Even though the average person's smartphone habit might differ from a "true addiction", both are potent sources of pleasure and both share at least one terrible adverse effect: namely, experiencing the pleasure frequently enough will tend to make it hard for the brain to stay motivated by "healthy" pursuits where the reward comes only after sustained effort.

In episode 33 of the Huberman Lab podcast (https://podcastnotes.org/huberman-lab/episode-33-dr-anna-lem...), the person being interviewed (a Stanford psychiatrist specializing in addiction) says that people who go cold turkey on their true addiction find that it takes their brain about 3 or 4 weeks to regain the ability to take pleasure in the normal healthy things, which is the basis for my belief stated above that indulging too frequently in easily-accessed pleasures on the web or on a smartphone can sap your motivation for weeks afterwards. Even if frequent smartphone use is distinct from true addiction, they both have a similar unbalancing effect on the central brain circuit for focus, drive and motivation (which involves dopamine).

ADDED. In retrospect, it would've been better if I had written this comment as an account of my personal experience, but I don't have time for a rewrite, and it currently has 5 points so I will leave it up. I wish I had written something like this: I've been an internet user for over 30 years. Curiosity is a strong motivator for me, and right from the start (30 years ago) I found using the internet quite pleasurable, Usenet newsgroups (then called netnews) being the initial source of pleasure and curiosity-gratification. I've always been aware of the danger of wasting too much time on the internet, but it wasn't till 3.5 months ago that it occurred to me that spending time in pleasurable pursuits on the internet might interfere with my brain's ability to keep me motivated during bouts of sustained efforts for weeks after the internet use. I then (3.5 months ago) put myself on a strict "media diet" and have found that it did increase my ability to stay focused and motivated. The lack of said ability has been a huge problem for me for decades; my ability to focus and persist at effortful tasks is still not great, but it is much better than 3.5 months ago.