Influenza has different strains. Swine flu, bird flu etc. When it spills over to other animals in antigenic shift is a once in 100 year event. Think Spanish flu. And virologists would say we are actually due for a similar event to occur for influenza specifically. That Spanish flu didn't have multi animal vectors. Swine plus humans. Questionable avian. Not like covid 19 at all.

If a deer has the flu, Hunter John who kills it typically doesn't get deer flu. And if he does, it typically doesn't spread beyond Hunter John. We are bathed in viruses everyday. There are phages for everything like plants and bacteria. Whether we have the receptors for the virus to incorporate into our cells is what determines if we get sick.

Let me be clear. We are talking about a cold virus that jumps into all mammal species. I'm not saying that covid 19 is lab created. I'm saying it doesn't behave like a cold virus and you and I should have some degree of skepticism about a bat origin