Yea, the paper you linked seems to hit the nail on the head.

“available evidence suggests that levels of ivermectin with meaningful activity against SARS-CoV-2 would not be achieved without extraordinary, potentially toxic increases in ivermectin dosing levels in humans”

And

“Very recently, preliminary findings on a potential effect of hydroxychloroquine combined with azithromycin against SARS-CoV-2 were widely publicized,15 leading to a surge in demand and self-medication, which resulted in serious harm in some cases and a stock shortage that jeopardized drug availability for other critical conditions for which hydroxychloroquine or chloroquine is the standard of care”

People promoting ivermectin really screwed things up