> If something has no legal uses to speak of, but has illegal ones
We are talking about making chemicals illegal as soon as they are discovered, or even before they are discovered. There's no way to know what legal uses they might have if no one gets to use them.
Due to this kind of stigma it's taken decades for people to accept that ketamine is one of the safest and most effective forms of treatment for depression, for example, while many migraine sufferers report that low doses of psychedelics are an effective treatment - something very dear to me as a sufferer of migraines, although unfortunately I haven't found that these work for me. Psychedelics are also a potential treatment for depression that needs further research. Then there's THC, an amazing drug for chronic pain sufferers and cancer patients, again mired in stigma because it's "illegal".
Sadly because reactionary politics it's taken decades to start to get legitimate testing done on these.
> dodgy... suppliers
Yes, when something is made illegal that's the only way to get hold of it.