If the individuals who have been peddling ivermectin and vitamin cocktails had instead encouraged enrollment in randomized controlled trials overseen by Institutional Review Boards to protect the rights and safety of human subjects, we would have quickly generated high quality data to determine safety and efficacy of ivermectin for COVID.
The haphazard global distribution of ivermectin meant that no meaningful data could be generated to determine if it worked.
https://www.forbes.com/sites/alisonbatemanhouse/2017/12/20/w...
The rest of your comments are distracting "whataboutisms" but to clarify:
• Airplanes may have good air circulation while the plane is flying but prior to take off and in airports, air circulation isn't so good.
• People were buying horse dewormer based on false claims about ivermectin. This is fact.
• As we learned more about the virus (e.g. the frequency of spread by asymptomatic individuals) and as the virus mutated (e.g. to be more infectious and not as "on target" for the vaccines), recommendations have changed.