Why would God not tell humanity explicitly about germ theory/antibiotics?
How many millions (billions?) in history died during childhood from something a quick round of antibiotics could have fixed? How many descendants do you think they no longer get to have? How many have starved because of pestilence which knowledge from an all-knowing God could prevent. Is it not incredibly cruel to make us figure out something as complex and tiny as bacteria? Sin may be the fault of man, but whatever version of creation you follow we did not create bacteria.