this all sounds a bit like Logan's run.
I suspect that accidental death rates were lower than they are today. Animal attacks were probably also somewhat rare, I doubt grok was hunted by carnivores. Grok and carnivores may competed for the same kill, but I suspect Grok rarely made it a life or death battle. Murder, who knows, probably. Grok would be more likely to fight with a neighbor than a tiger.
Grok died of what we die of, infection, disease, and starvation. Things brought on by poor nutrition and stress - surprise, surprise. When food was available, he was healthy. When it wasn't he suffered. Winter was hard, drought was harder. It has also been observed in bones that he suffered from arthritis. That's right an inflammatory disease! Lets face it, at times Grok had to "over train" he had to lift heavy and carry heavy things day in and day out, there were no rest days.
It doesn't mean that living the Grok way is wrong, it just means that life was hard for Grok. We are trying to learn (remember) how to live like Grok in the best of times, not replicate all aspects of his life. Doing so would shorten yours.
It's grandma, but you can call me sir.