As someone who has built a career in building and maintaining digital services, a lot of what Carmen talks about rings very true to me, especially this part:
"The platforms make money based on the time we spend on them, and they don’t hesitate to use unethical, addictive resources, so how are you going to ask a 10-year-old or a 13-year-old to stop, if it’s even hard for us adults?"
I've struggled with social media and technology addiction myself, so in my mind, allowing a child a smartphone is akin to teaching them how to smoke - that is how toxic and generally "bad-for-your-health" modern internet is, I think.
At the same time, I am not (yet) a parent, so I really don't know how am I going to be making such a decision when the time comes.