> what is wrong with ancedotal evidence
nothing really. you do formal studies to answer questions, raise certainty and satisfy doubts.
doctors are required to obey the FDA and the AMA or their license gets revoked. the AMA is a scam/inversion who was founded to combat the rise of homeopathy organizations. those organizations actually STARTED the idea of licensed practitioners, testing medicine with provings, keeping detailed journals on effects on themselves or patients. the AMA then later became full arbiter of medicine in the USA, and used this authority to close down every medical school and revoke licenses on anyone who practiced any medicine that was not either surgery or drugs (conveniently, roth/rocks own a lot of drug patents.)
a placebo-rct is the gold standard because it makes it almost impossible for shenanigans to account for your positive results. in theory this should also be replicated by others to make sure you didn't just lie or conduct many studies and keep the good ones. the part where they obsess over expensive placebo-rcts while not enforcing independent replication too, is just to keep things expensive.
its important for things to be expensive because an old drug with an expired patent like HQC has almost no chance of raising enough venture capital money to spend the hundreds of thousands needed for some private citizen to do a placebo-rct with hundreds of candidates. a vaccine company however is going to make some "novel" genetic disaster, patent it, and get governments to funnel millions of dollars of stolen citizen cash.