less sarcastic answer, if drugs are the thing that makes someone's life tolerable and livable and even pleasurable then it would be uh, pretty fucking hypocritical of me to take issue with them using
even less sarcastic answer, you are overestimating the extent to which the danger of even "very hard drugs" (define that) comes from the drugs themselves rather than from the conditions of use: insecure supply driving desperation and making overdose more likely; black market making overdose more likely; intolerable conditions of living making using more necessary; &c. i can't speak to your life or loved ones but in my life i have observed and engaged in many different patterns of substance use, ranging from 'casually & occasionally using substances w high addiction potential' to 'intensely and compulsively using substances w much lower addiction potential' and everything in between. you are also jumping from "drugs" straight to "very hard drugs" (again, define that). drugs is an inclusive category: you need to be thinking here of substances ranging from heroin to caffeine to ibuprofen to xanax to ayahuasca to surgical anaesthetic cocktails.
really dead serious answer, yes, drugs can be dangerous. so can driving, working, and exercising. drugs can also be immensely beneficial, and that goes for drug use that's 'purely recreational' and pleasurable. as a matter of basic self-determination and autonomy, yes, i will defend people's right to get high for any reason they choose. as a matter of basic prison abolition politics i will defend that right twice over. i will also defend needle exchanges, social (not state) support systems, and the communist project of making the world a just and tolerable place to live in. but humans have enjoyed substance use for literally millennia, i personally enjoy substance use, and i don't think fearing it is politically useful or interpersonally helpful. at core, 'drug use' is simply the consumption of a substance that alters a person's psychological or physiological functioning in some way. it's not inherently 'good' or 'bad', morally or from a health perspective. what it is, though, is a common part of human existence, and not one i think can or should be eradicated.