Because the "experts" haven't been experts in much except for getting things wrong and lying to the American people.
The facts are that Covid-19 basically burned itself out before the first shot went in the first arm and that none of the mitigating factors prevented net deaths from occurring; in fact all these mitigations, from mask orders to lockdowns to closing businesses and others caused more deaths due to ODs, suicides, avoidable heart attacks and strokes not screened for and other maladies by a wide factor than the mitigations, even using fatally flawed claims taken on faith by these very same agencies, could have possibly saved. The actions we could have taken to actually reduce death, specifically as regards care home and other medical facilities we deliberately refused to do and we knew those actions would save lives. Instead of protecting the most-vulnerable while those least-likely to be seriously harmed were naturally infected and built a wall of population immunity we deliberately refused to protect those older and sicker people from infection via the health care system and they died.
Given this record of falsehoods, actions and intentional refusals to act you're willing to bet your life they're telling the truth this time?
I had little faith in a lot of institutions prior to the Kung Flu. That faith has essentially been burned to the ground and blown away during the past year.