Was recently speaking with a retired doctor (87 yo) who knew 2 doctors that worked during Spanish Flu and one thing he brought up that I didn't know at the time was the large dosages of aspirin that were being recommended (and taken) during that time since it was the "wonder drug" (his words, not mine). Point being some people were probably dying of aspirin toxicity and may have distorted the numbers and there is some information, albeit controversial but plausible, that is out there but until he brought it up would never have looked it up.I recall my mom showing me around the cemetery where all her relatives were buried. She could point out grave after grave (friends and neighbors as well as relatives) who had died due to the 1918 pandemic. She remarked that she should have been there as well!
Will be interesting years from now what treatments being done today will be looked back on as improper but, unfortunately, that is how science evolves and learns.
Example:
https://www.sciencedaily.com/releases/2009/10/091002132346.htm