Medicine of course is the critical tool - but the main reason these people died was a cruel and hateful US administration that wanted them dead, and didn't wish to take any action, even to the point of abandoning personal friends. They didn't acknowledge the disease even existed for 4 years after doctors had identified it in New York and LA (imagine an administration pretending Covid didn't exist from 2019 until 2023), and a mostly-ambivalent or ignorant populace worldwide.

I remember it was not uncommon to hear people saying the 'gay disease' will 'solve the gay problem' even into the 90s due their conservative bigotry.