I'll try...
Fentanyl is drug, legally manufactured in China and used in clinical trials which, when used correctly and within the laws, can facilitate treatment of Addiction, PTSD, and depression.
Also imagine how many animals are killed by cars. And how many habitats have become uninhabitable to the toxicity of the tire and exhaust pollutants.
Legality is flexible and can usually be bought by the highest bidder. And just because cars are obtained legally, doesn't mean they are used as the manufacturer intended.
With fentanyl, we should stop blaming the homeless person and blame the manufacturer of the drug. In the same way, we should also stop blaming the drivers for killing people and blame the manufacturers that lobbied to make automobile transportation the only way to get around.