Has anyone ever shouted, Quick! Sun-salute for your life! Of course not. But you hear Run for your life! Climb for your life! Don't worry, I´ll carry you out of here! all the time.
Humans made yoga up for recreation, not for survival. No animal would ever do it. Changing postures in the same place with your head down? Forget it!
In the wild, that's death. You need the luxury of a no-danger environment for yoga. Everything is controlled – the soft mat, the temperature, some gury telling you what to do. It's not instinctive or natural. It's make-believe.