The are randomized trials being conducted, wait for better science to come in before writing it off.
Is it so bad to have a medicine for treatment? Should we not be looking at all possibilities still? There are open questions about the long term and variety effectiveness of vaccines. Seems best to have as many tools in our medical toolbox as possible.
Spreading unproven claims could, for example, cause people to rely on Ivermectin instead of getting vaccinated, which would be an extremely dangerous bet with almost nothing to win and almost everything to lose.
(politics alert)
This is being stoked by certain media and political organizations. It's a political wedge issue--GOP stokes their base, keeps/gets new voters on this issue, then gets in power and robs the country/planet by doing the bidding of donors/corps/lobbyists.