"… authoritative health bodies (FDA, WHO, CDC) …"
All three of them are in bed with "Big Pharma" from which they receive very substantial proportions of their annual budgets.
Just to give an example, the WHO's principle funder is the Bill & Melinda Gates Foundation [name may be changed now].
Research studies funded, directly or indirectly, by the pharmaceutical industry have frequently "proven" the ineffectiveness of un-patentable remedies (e.g. mega-dose intravenous vitamin C therapy first developed by Dr Klenner, and then promoted by Linus Pauling, two-times Nobel Laureate, in association with Dr Ewan Cameron). How do they do this? In general, very simple. They use non-therapeutic doses for their "research".
Might be worth a glance: https://pmc.ncbi.nlm.nih.gov/articles/PMC6940627/
However, you are free to believe what you want and support your beliefs with the evidence that fits. There is no shortage of it, as the pharmaceutical industry is financially very powerful and intends to remain so.
[And Google's search algorithms are these days programmed to favour the conglomerate's financial interests]