The body is an amazing machine. It's still a good idea to at least try to understand the basic processes before making experiments on it. At least understand how ketosis works and why it isn't our default mode of metabolism.
While there certainly are people who feel that it is helping them, others would be actively hurt by it. Results on one individual can not be extrapolated into some sort of universal cure. The fact that such advice can be readily found on the Internet anyway probably shouldn't come as a surprise though.
It is the default metabolism.
1. All things being equal if you do not introduce any calories into your body you will naturally be in ketosis.
2. The only way to be kicked out of ketosis is to elevate blood glucose levels/spike insulin. Sure that is nearly everyone now, but that doesn’t make it the Body’s default...you need to eat a certain way for that to happen, historically there really wouldn’t have been a ton of available options to Eat Foods to kick humans out of ketosis until humans began farming grains and cereals.
3. Perhaps most importantly your brain can run off of ketones or glucose, very few things can cross the blood brain barrier, and ketones are far more efficient at crossing the blood brain barrier and powering the brain.
The important issues I found have to do with “keto flu” (you have to supplement elctrolytes or you’re likely to feel bad with weird symptoms for the first few weeks) and with some pre existing conditions; otherwise keto (and IF) seem to be as safe as any other diet, and likely much healthier.
Did you reach other conclusions?
While true, it's also a lot like calling the Internet a "photon transport mechanism".
If you experiment with such things, make sure you get the whole picture and is otherwise healthy. Ask anyone with diabetes why.