I can't re-find the Youtube video on the fact that H1N1 almost not circulating during COVID. But there is one out there if you can find the search terms.

Basically the different families of human virus don't co-exist in one body. Maybe not totally true, but for most healthy and many unhealthy people that would be the case. The statistics are fuzzy at the population level because of the distancing measures, but in one body the evidence is clear. H1N1 is not a problem at the moment, and the research, such as it is, has not come up with firm conclusions.

Interferons in the nose generated during a viral attack that is well under way may be too much for a smaller viral load in its initial stages, is one postulation. Or maybe like plants secreting unctuous stuff to deter competition, who nose? (sic).

no, I don't know what they are either!