It is completely unreasonable for a society to do a careful cost-benefit analysis of everything in society - it's completely reasonable for a society to identify highly harmful things (especially those that hijack our brains through direct chemical or emotional addiction) and police those, or, as per Portugal's approach, make available societal supports to allow people to better cope with that addiction. The later isn't very reasonable to expect in a world of rising austerity due to financialization so the former seems more realistic.

"Hijack our brains" - exactly what I mean by pretending people don't have agency. Who gets to decide what counts as hijacking and what is just normal culture? Anything is "hijacking" to some extent - boy bands hijack teen girl brains, the BBC created Teletubbies to hijack toddler brains, heck any artistic representation is a hijack to the extent that it is interpreted by your brain at least partially as something other than what it really is i.e. some colours on a flat surface. The point is a new form of culture, communication and coordination is emerging and the old powers are shitting their pants.

(Fully agree on the Portugal approach though. The difficult to accept answer is that if people are choosing a shit life of scrolling 10 hours a day maybe we should do the actual hard work of improving the kind of life open to them.)