HCQ is not 100% solution, and so are masks and vaccines. Even Dr Z mentions that in his opinion only young & healthy might not need vaccines. If you look at costs/benefits, if I understand your concern correctly, then you are questioning whether ALL young & healthy, even those who are not sick, need to take a risk of vaccine if the benefit is marginal.
How do you compare it with HCQ, vitamins – preventive measures also involves healthy person taking these substances. Just because a chemical is called “vitamin”, does not mean it is a chemical that affects the body. For sure, HCQ was never taken by whole population – and you have to take these repeatedly v. 1-2 times for a vaccine. If you are talking taking them only when sick, it is not clear whether all people are capable of selecting the right time to get it, and also it does not prevent you from passing virus to other people, while SD, masks, and most likely vaccine do. Plus consider remaining uncertainty of medical opinion, I think Yaakov had higher confidence in his zechus than we do.
If you are still not sure, use a mussar approach when you are not sure whether your opinion is unbiased or you are simply lazy, physically or intellectually: expend the required effort and then think again. For example, go buy masks, wake up early to go to an emptier store, learn at home and teach your kids one day a week. This should not hurt much.