Also, I'm not qualified to judge a paper by its work quality, I need to rely on the experts in the field for that, and a decent proxy for that judgement is where a paper gets published, so by looking at where a paper was published, I am judging a paper by its quality.
Impact factor is not a measurement of an individual article’s quality. It is a summary statistic, a rough measurement for how frequently that particular journal gets cited in other journals.
By judging an individual article by the impact factor of its journal, without reading the article and determing its quality yourself, you bias yourself to whatever those results might be one way or another with a statistic not intended to relay any information about the journal article itself.
You are right that it is a decent proxy where higher impact tends to have better journal quality (anecdotal, but I have observed this for sure) but I got annoyed when you claimed an article published in a low impact journal had no merit. That is simply not the case.
You can have the best, high quality scientific study ever about a highly specific thing, but because it is so specific you won’t have the broad impact that would get into one of the top tier journals. But with your viewpoint, that study would get thrown out the window.
Also, for what it's worth, most of the articles referenced in the Harvard Medicine review referring to dosages are from before 2010, so they may be out of date.