I am listening to the audiobook "Stolen Focus" and it has some good points on internet addiction. Most importantly, it's useless to blame yourselves completely for the addictive behaviours. The tech industry is spending billions on experts to get you hooked. In a way, tech industry is like Purdue pharma. But the responsibility is still individual's.
The way I like to think about it is that lots of people or places might be responsible: society, big industry, governments failure to regulate, so on and so forth. Those are interesting academic, or political discussions if we're talking about collective political actions that we might take.
On the other hand, understanding that you are addicted, and why, are the first steps towards individuals feeling empowered to quit. Which, in many, if not almost all, cases - they absolutely are able to do. And it certainly improves their odds if they have a network of supportive friends, family, and the like.
For someone who isn't an addict, taking a non judgemental and understanding approach to get the addict to ask him or herself those questions or set themselves on the path to recovery may be a way to meaningfully help them. But it can only really work if they're already open and receptive to that. And that depends, to a great extent, on what your relationship is with them and how much they trust you.