Sounds like this guy is in the category of people for whom keto diets can work wonders. It's definitely not worth it for me, I've tried, and I suspect it's the same for most people.
Have you tried low carb? I tried keto for a while, and noticed a few benefits, but it was hell not having the occasional bowl of rice or slice of bread. So I switched to a mostly low carb diet, but allow myself to have things like rice and bread 1-3 times per week. I’ve found almost no difference for me between this and keto in terms of physical benefits.