From September 2022:

The number of reported Covid cases is currently a quarter of what it was at its peak last winter. But Chris Murray, director of the Institute for Health Metrics and Evaluation, estimates that only 4% to 5% of infections are being reported, because so many are uncovered through at-home tests and aren’t reported to public health departments, or they aren’t being detected at all.

The decline in PRC testing and a shift to at-home tests also leaves public health officials increasingly flying blind with regard to the spread of infections because few at-home test results are reported to public health departments, unlike with laboratory tests.