The modern approach is decriminalize small amounts, and treat addiction as a disease instead of a crime. The results speak for themselves.

Very few people believe "all drugs should be legal", that's a complete misrepresentation.

Accompanied with drug treatment provided to all, yes, that's a very popular view here.

What drug treatment is available for sugar addiction to people who are self-harming and don't know how to stop?

If classifying it as a drug solved that problem by feeding all human beings healthier foods, so that they can get their caloric intake without industry-cheap sugars, I would absolutely be on board with that :)

It's consistent to believe that some foods/drugs are bad for your health, yet should still be legal.