Keto has no solid association with any improved outcomes in terms of stroke and CVD. The gains are typically because of weight loss in which it is just another variant of CICO. You'd make the same gains in health by simply eating better overall and in accordance with your activity level.

Keto however has numerous well researched negative health outcomes such as elevated LDL, ApoB, etc and these can be dramatically elevated in hyper-responders. Though, the science is also out on if mildly elevated LDL is anything to worry about. It's not a panacea but rather a trade off. Most people can stick to keto better because fats simply taste better and keep you feeling full longer and the alternative is much harder to stick to long term.

It is only known to be effective for treatment resistant epilepsy. Any other benefit either can be equally attributed to the control (CICO + exercise) or are pseudoscience.