I was just writing something similar but you put it out so well here.

You can "observe" how Jack and Jill do with ivermectin but it's not clinical trial until you have statistically comparable and significant groups of jacks and jills with covid and give half of them ivermectin and other half placebo.

In all honesty: You can't say how well a certain medicine does until you also see how being without it affects person. You can't compare different countries with genetically different population, different season, population density etc. as such.