I think one big missing element for the reasoning behind all this is that people seem to intuitively assign the wrong prior to the chances of a zoonotic event, they miss that fully 2/3rds or so of our pathogens are zoonotic in origin, and that's only the ones that we can trace back, the remainder is either an open question or settled to have originated in our species or passed on as part of our heritage prior to humanity budding off from our ancestors.