Why not?

I either pay $150+ all up for a doctor visit, prescription, etc for antibiotics, or $20 for a bottle of "fish antibiotics" at the feed store. Either way I get amoxicillin; but from the feed store I get 3x the amount and in smaller capsules which makes adjusting dose easier.

We stock the "horse paste" ivermectin for our half dozen hounds, I've been known to have a lick of it myself when ive been out barefoot in the mud, just in case. we have whipworm out here and they're not likely to take in humans but when they do its nasty.

In the US, there isn't a taboo against taking it because it's generally animal-prescribed; it's used as a human anti-parasitic here too. The issue is that people are self-medicating with veterinary-supply doses because it isn't prescribed for COVID-19 (as it's not indicated for treating it).