> And prehistoric game meat is also not the same as farm meat. Beef and pork contain high amount of saturated fat, but game antelope would contain much less and would have unsaturated fat. Meat of that time is really closer to avocado than meat of our time.
Wild meats have very different ratios of fats that farmed meats, but mostly in the opposite direction you are saying. Because (especially non-ruminant) animals take most of their fat from their diet, rather than synthesizing it directly, farmed meat closely mirrors the ratios of fats fed to them via diet- and using seed oils in animal feed makes them have much more omega-6 polyunsaturated fat, and much less saturated, monounsaturated, and omega-3 fats.
Overall a high omega-6 intake is a huge problem as it alters our cellular lipids in a way that impairs a lot of systems, as is eating muscle meat only which has weird amino acid ratios compared to our needs. Weird amino acid ratios in diets have different usually undesirable drug like effects. Both are major issues for anyone trying to do a 'high meat' diet in modern times. As with vegans, if you deeply understand this stuff and have the time and money you can probably make it work.
> whatever pathetic adherence rate a miserable existence like ketosis has
Ketosis seems pretty effective for some people and not for others. I did it for many years and felt amazing- it was in no way "miserable" but eventually got into competitive sports where my performance just wasn't as good with a restricted diet. If I were diabetic, there is no way I'd rather be insulin dependent than do a ketogenic diet, assuming it actually worked that way for me.
I know several people that permanently solved major mental health issues that didn't respond to other treatments by staying on ketogenic diets.
For many people, I do thing higher carb diets actually are better for diabetics, because low carb induces extra insulin resistance and raises blood sugar levels. The most effective diets I have seen in peer reviewed research for diabetes treatment seem to be something like "high carb paleo" diets with lots of starchy root vegetables. However, if it makes it easier to lose weight and eat less for someone, ketogenic diets will help.
Moroeover- and this is little known I think- ketosis and low carb are really totally independent things. Ketosis occurs anytime there are excessive acetyl groups in the TCA cycle, which happens under various conditions unrelated to carb intake.
Most people on low carb diets never get into ketosis unless they also severely restrict protein, because we make a ton of glucose from protein (via gluconeogenesis). People eating mostly lean wild animals are unlikely to ever reach ketosis- you'd have to be eating mostly things like seal blubber.
However, many people on high carb diets, especially things like raw vegan diets or diets with lots of resistant starch, e.g. from potatoes and rice are in ketosis, because resistant starch gets ultimately metabolized as ketones. The so called "keto diet" is probably not actually a ketogenic diet but "raw veganism" and the "potato diet" probably often are ketogenic diets.
I don't really have a high vs low carb bias or preference but think it is fascinating how adaptable metabolism is (and it is what I research professionally).