They lived the simplest life “people created computer to solve problems that never existed”

You know, humans are blamed for discovering agriculture? Why? Because before that our ancestors readily provided themselves a quality food(with all nutrients). Obviously, by chance. Like they eat the grass, the snake, the sheep, the fish, literally everything. 2. They were very scattered. There were no villages, cities, countries back then. At the time, no risk of infectious diseases. 3. They were well adopted to the environment(they got far effective immunity than us) . They walk naked in Siberian ice wall. They eat most of the things raw as long as they were edible(of course they had already invented fire but use it for specific purposes). 4.there were no much numerous risk factors or diseases. All this bacterias, viruses and parasites evolved over time. Now the sum wraps up your question.

B/c of the comand of God

He used to eat whatever he likes freely, no one bother him, no pandemic since there were few people in specific location

Because they were living in the God's way. They were not sinner as we are. Well everyone is sinner but they at least have a fear of God