Almost everything in medicine ends up being surprising. So much "knowledge" is just someone's assumption being passed as gospel only to be discovered false yea

Almost everything in medicine ends up being surprising. So much "knowledge" is just someone's assumption being passed as gospel only to be discovered false years later. Medicine isn't an engineering problem. There is an analogy in software engineering where people argue about the most "efficient" way to do something and don't bother profiling it with real world data. There are consequences to advising people that their masks are half worthless, if it is not true. People might not be willing to wear valveless N95 masks. Or they take those masks off more and expose themselves more. Asking for a little data behind a recommendation is more than reasonable.