I'm not sure your post, while true, is responsive.
Rules are naturally infringements on individual liberty. The question is, which rules can one justify? Put differently, when can the state limit individual liberty? And that naturally raises the question: why is it appropriate in some cases, and not in others?
Your justification points to the consequences to the state in terms of economic cost and I suppose the psychological trauma suffered by emergency personnel.
Let's push your logic further. I understand you're posting from NZ, and I'm posting from America, but we face a drastic obesity crisis here. For the sake of argument, let's stipulate that the main cause of obesity is overeating, and if we restricted the number of calories available to people we'd see a drastic decrease in healthcare costs and so forth. Should the state be allowed to control the food you eat, the number of calories you consume, etc.? If not, why not? Could the state make obese citizens go exercise at state run gyms?
Or consider the effects of social media use on children. There is at this point pretty good evidence that social media use by teenagers, especially girls, leads to negative mental health outcomes (mood disorders like depression, etc.). Can the state limit the amount of time teenagers spend on tiktok or instagram?
My point is, individual choices always have effects on society, insofar as any individual person is a member of a society. The fact that individual choices have negative effects on society broadly cannot itself justify regulating those choices. The justification for state power must be found elsewhere, imo.