Some people seem to get even better relief from some health problems by going carnivore = eat only meat or animal derived products. Some that saw improvements with keto got even more improvements with carnivore. Some people are sensitive to certain foods. By going to a meat only diet for a period of time it becomes an elimination diet. Then after improvement a person can introduce foods one at a time to see what ones are the culprits. 

My wife and I have transitioned over time to a mostly meat diet. Still a few vegies once in a while, but 95% meat and most of the time 100% meat. Eating out is when we most likely will eat a side of vegetables because of limited choices. But at home we just don't buy hardly anything not meat or animal sourced. It seems to work well for us. Others results may vary.