One big problem is that that the CDC and other authorities failed miserably at reminding the public that their guidance was often based on weak, but directional

One big problem is that that the CDC and other authorities failed miserably at reminding the public that their guidance was often based on weak, but directional evidence. The net result given other dynamics was people taking it to be gospel or bullshit, and when reversals occurred it was memory holed by the former and taken as vindication by the latter.