I'm pretty sure somewhere in the American South they have deep-fried bacon toffee. They have bacon everything. Sprinkled on a bottomless bowl of fries...
They also have the highest rate of diabetes, heart disease and bowel cancer in the western world... west aside, probably only bettered by the Vodka guzzling coutries.
I don't share your optimism on the "low risk" associated with processed meat
Anyway, back to ketogenic... I am not so sure we evolved as "fat eaters", our ancestors (and by that I mean apes rather than Neanderthals) have a diet largely based on sugars (simple and complex) and fibre and our digestive system is not at all dissimilar to that of a chimp BUT a lot different to that of rodents (as an example of fat eaters) or big cats (as an example of pure meat eaters)
Humans are omnivorous, as such we do best eating what we can find. We don't have the adaptions to digest large amount of fibrous vegetable matter or to handle large amounts of protein. We certainly wouldn't have had the opportunity for large amount of fats or meat, the problem with animals is that they run away, catching them is energy expensive (and as mentioned, we're not very good at digesting the result).
Humans have, with few exceptions, got the majority of their calories from unrefined carbs (grains, fruit, starchy veg) for as long as we know, that's probably why we started farming grains. It's easier to catch a potato than a tiger, and you're less likely to be eaten by a tiger if you don't spend your day in the middle of a field munching grass.
Anyway, eating large amounts of fat is well-established to have adverse consequences for cardiovascular health. But like anything, fats as part of a balanced diet are fine. Of course, the fats-are-bad narrative drove the entire low-calorie market, which primarily replaced modest amounts of fat (yes, yes, bacon butter, also a thing) with less modest amounts of sugar and salt.
Meanwhile, on the subject of
bacon toffee fries.