What evidence do we have that the Covid NPIs were actually successful in suppressing other viruses (but, notably and strangely, not Covid)? Empirically speaking

What evidence do we have that the Covid NPIs were actually successful in suppressing other viruses (but, notably and strangely, not Covid)? Empirically speaking, viral interference may fit the facts better than "masks work against influenza but not SARS-CoV-2": https://www.statnews.com/2021/01/31/a-viral-mystery-can-one-infection-prevent-another/ https://www.statnews.com/2021/01/31/a-viral-mystery-can-one-...