I've seen people mention this here and there but tbh I feel like this is a pretty big question that scientists and the media aren't doing a particularly good job at covering.
Ever since COVID came on norovirus rates have absolutely plummeted? What's going on? Is this about how medial professionals are categorizing or something else? Like the article talks about hand washing and masks being a possible reason that flu rates have absolutely flatlined, but I feel like you'd really have to suspend your common sense to think that just those things alone would cause flu rates to drop 100x, that's an astounding drop.
https://www.washingtonpost.com/health/2021/01/12/covid-shutdowns-viruses/Quote
These other viruses — including influenza A, influenza B, parainfluenza, norovirus, respiratory syncytial virus (RSV), human metapneumovirus — all appear to be circulating at or near levels lower than ever previously measured. The same is true for the respiratory bacteria that cause pertussis, better known as whooping cough, and pneumonia.