I'm sorry, how much money do you think professional runners make that it affords them some crazy diet that the general public can't tolerate? Not even professional runners for that matter-- college runners, or even high schoolers. My partner and all of her colleagues that compete at the international level in Canada have part-time jobs. My partner is in grad school full-time at the moment, too. They aren't "abusing their body" as much as possible, they just do a lot of base mileage, two key workouts a week, and recover and eat properly-- and they've done that for years. That's the secret.
I eat with, and cook for my girlfriend, and I am a brutally normal guy in the military. We just use standard ingredients and try to cook things from scratch. We have pizza and/or go out to eat about once every two weeks or so. This isn't purely anecdotal, it's completely reasonable to run a 120km/wk and maintain a normal life-- that's most elite runners on the field, and I make that assessment as a guy who has been in these circles through my partner.
I would disagree with your assessment of "unstoppable" versus "fastest". You can certainly have both with carbohydrates. Moreover, given the parent comment wanted to get faster, I would probably not reach for keto under your recommendation.