It is dangerous. Proper dosage and monitoring are necessary to guard against risk of QT prolongation and retinopathy. It's possible for it to be true both that it saves millions of lives and that it's dangerous to take unsupervised.
> A drug with a 10-50% success rate will still save a lot of lives.
There is zero evidence that it has anywhere near that level of effectiveness, even when combined with zinc and azithromycin for the most favorable population and conditions. It might have some effect, but touting it as a miracle cure when other treatments are already known with greater effect and lower risk is irresponsible.