I'm not very convinced by this argument. First your alcohol example is working against your point as alcohol costs billions in damages. Some sources argue that alcohol is very similar in costs:

For example I'm reading that US CDC estimates 249B usd damage from alcohol and 300B from smoking so they are very much the same.

That being said, my main argument would be that prohibition just doesn't work and it's so hard to determine lines. Should we ban excess calories like fast foods or just butter because obesity is by far the biggest expense and we know that food is extremely addictive. Policing every activity at this level seems impossible.

We already have a solution for this burden - tax. You won't get any taxes if you ban smoking and still have to care for smokers.