A quick summary of my past, I had health problems that were so bad I had to leave a tech company and a job I loved. I was literally dying. I am still not working other than on improving my health, but the severity of the situation led me to try radical things like a carnivore diet. I am 49 years old currently and have tried various diets in the past, including veganism and various plant-based diets. I had no luck with any of them. I know people that have, however, so I think whatever works for you, great!
That said, and while I am not a doctor or any type of expert other than someone willing to test things as objectively as I can, my personal experience was that this is very nutrient dense and safe. The diet is super simple, meat and water. Although I usually opted for grass-fed rib-eye steak and almost all of it was cooked with a Bar-B-Q. Other than that, some coffee with cream, but that cream would be about the only carbs taken in.
This diet was for about a month and I have now transitioned into a modified Keto diet. Take the Keto diet, then slightly less fat, more protein, that is what I am on now. As for the results, my hypertension and high blood pressure are now normal and not on the verge of organ failure. I have also lost about 15 lbs over the 30 days, which is quite a bit as I am not that much overweight. The best thing about the diet is how easy it is. It is super easy to just buy steaks, burgers, salmon, meat, and just cook and eat it.
Many diets are complex, hard to stay on, and even the Keto diet I have to pay way more attention to portions, timing, and really I think intermittent fasting needs to be mixed in to really work well. The carnivore diet just works regardless of the timing or how much I snacked on beef jerky or whatever. The first couple days there was the normal carb addiction to get over, but it was trivial. Sugar cravings all went away. I finally quit the carnivore diet and moved to a Keto diet just for the variety a few days ago. The Keto diet is much harder, but I like the variety. Now, the carnivore diet didn't cure all my problems, but the weight loss was useful and I know I can always go back to it to lose more weight easily and safely.
As for the fears about it like colon cancer from red meat, those studies were very biased and mostly from vegetarians in the EU. They say it doesn't matter, but it actually does in my view. Heart Disease and other problems could still be a risk, but compared to diabetes or just dying early in part from the SAD, Standard American Diet, I think anything is better. Veganism, Paleo, you name it. Anyway, if you want to try it, really nothing to it and if you have any type of weight problem I bet you lose a bunch of it. Which is always nice, and the easy part I really liked.