I would caution that just because your body can make something doesn't mean it will have optimal performance when doing so. People in ketosis do have worse peak performance in sports than those that eat more carbs/sugar.
This is true, but I don't think our understanding of nutrition is good enough to really pick and choose what we want to optimize for. Eg we still don't have a recommendation on whether we should costume external vitamin K2 or not. The same goes for many amino acids. Some of the non-essential ones can have interesting effects when taken alone, eg glutamine - seems to help the gut lining. (We also don't know whether that's perfectly safe due to cancer risks, because some cancers eat glutamine.)
Your mind and health are impacted by your physical body. If eating a certain way impacts your physical performance then it might also have effects on your health (and mind) in unexpected ways.
I'm not saying that ketosis has this kind of an effect, but rather that eating or not eating some other things might. Eg vitamin K2. The body is be able to make vitamin K2, but we might have stronger bones and teeth, and a healthier cardiovascular system, if we get extra K2 from an external source.
