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.