If you visit a developing country, you'll still see people bathing and washing clothes and cookware in rivers. You'll also see outhouses on stilts along the same river. While there's a high incidence of illness among people who live like this, many people clearly tolerate it well. If I were to do that now, I'd get sick, but eventually I'd probably be able to tolerate it as well (assuming I survived).

It's a common misconception that animals don't get sick from tainted meat or water. They do, and when they're weakened enough, they get eaten. Clearly some have a higher tolerance of certain pathogens (e.g. vultures), but many succumb to intestinal bacteria and parasites at alarming rates. We just don't see it.

First, you or I probably could eat raw meat from a freshly killed wild herbivore with very little risk, compared to raw meat from a modern cow, raised in crowded conditions, handled by dozens of other humans, and pushed through various surfaces.

Also, there's a theory that fire and cooking is part of what allowed hominids to develop their superior brains and leave the trees behind for a fully savannah-based lifestyle.

I'm not sure about that one.

As a species we need to stay in groups and take care of our sick. We traveled vast distances by foot and sought out our own kind.

To equivocate, I did hear about ancient ruins of villages in China where unknown strains of plague were unearthed, before this COVID-19 stuff. I assume these then became cursed villages that no one visited.

Are the same pieces of meat involved?

Lots of grocery store meat that you buy "fresh" was killed x number of days ago.

If a dog eats raw meat within a few hours of it being killed, it's a big difference.

How did I come to this opinion? Try freezing a super market steak a few days before the "expiration date." Then unfreeze it a few days after the expiration date.

You'll notice a rancid smell immediately upon cooking.