First, this is a straw man. Nobody is saying that the CDC's guidelines are infallible. They've been widely criticized for botching the Covid-19 crisis.
Second, the difference between CIA, FBI and CDC is that usually when the CDC makes a pronouncement, it is linked to some scientific basis. Unlike the CIA that can claim Iraq has 'weapons of mass destruction' based on vague evidence that nobody - except for a handful of legislators and the president - get to see, one can go and track the science behind a CDC's announcement relatively easily.
Second, the difference between CIA, FBI and CDC is that usually when the CDC makes a pronouncement, it is linked to some scientific basis. Unlike the CIA that can claim Iraq has 'weapons of mass destruction' based on vague evidence that nobody - except for a handful of legislators and the president - get to see, one can go and track the science behind a CDC's announcement relatively easily.