Other "natural" substances:

Tobacco
Poppy (opiates)
Mushrooms
Coca
Etc
Etc

For the record I have no ethical qualms about using cannabinoids appropriately for pain (especially malignant pain); but the argument that weed is "natural" and therefore safe is misguided and deceptive to a vulnerable population (young people). I have a patient who is on oxygen 24/7 due to smoking weed for 30 years. He has never smoked tobacco. He can't walk across his living room without stopping to rest. He has COPD.

In my experience, oral THC is often as effective for cancer pain; and clearly safer than smoking or vaping. My experience is limited to a few years while in training. I'd be interested to hear from a pain specialist