I believe it is at once possible to both blame or seek to change an extrinsic factor and do what one can with their own initiative. I do not think it is appropriate to dismiss extrinsic factors in order to emphasize personal initiative.
We can list extrinsic factors that influence things for hours, but nothing changes the fact that using your phone for hours per day is a choice that people make.
The external factors are brought up as a way to distract from that choice or shift blame, but you can’t make progress until you realize that it’s your choice to pick up the phone and use that app for hours every day.
Yes it's a choice to pick up the phone, and yet if someone is feeling an emotion and wants to escape that emotion, the phone offers a variety of other emotions they can access. I'd say quite addictive, unless people let themselves feel the feeling.
But when it is an entire system (eg, not just me) I like to look at the gravity. In what direction will a ball roll? By default, what occurs here?
Take my home for example. I’m skillful at being calm and joyous, but I have guests come over, so I need to make sure that my home fosters a calm and joyous mindset by default. I need to make the gravity of the space produce joy and calm without intervention. After all, might I one day lack agency or otherwise be vulnerable to preexisting environmental forces?
We each have a duty to be healthy. Personal intervention — check! I agree. But that is not enough, we cannot stop there, and stopping there is irresponsible, unkind to others in the short term, and dangerous in the long term.
Unfortunately, your family, friends, and bosses aren’t going to be convinced when you try to explain that nothing is actually your fault.
You do not have the ability to stop being you, the person who wants the things that you want. Even if you want to change yourself - and maybe succeed! - that desire for change is still part of being you. If you didn’t want it, you would have been someone else.