The outcome could have been much different - and many lives saved - if Big Pharma hadn't been so successful at suppressing this generic pharmaceutical that was found to work against COVID-19.
https://conservativeplaylist.com/2022/10/09/the-war-on-ivermectin/
An explanation that requires fewer assumptions: The rich and powerful do not want second hand smoke near them, and something was needed to replace the profit from treating lung cancer.