As a counterpoint, Japanese people generally eat almost the inverse of the keto diet (high-carb, low-fat[1]) and have the longest life expectancy on the planet.
It's just not as simple as "this diet" vs. "that diet".
One interesting thing to note is that much of this comes from Okinawans in particular, and there's a possible link to a purple sweet potato they consume a lot of (or at least used to). You can get them at most asian grocery stores and they're quite tasty (but not especially keto friendly).