Adam Ondra is a vegetarian, I guess that's whats holding him back.
I've read up on recommendations for protein quite a bit, both in physiology textbooks and recommendations from various health departments around the world. 0,8g/kg/day is for sedentary up to exercise for three times a week. Some countries recommend slightly more. For competitive weight lifters up to 1,5-2,0 g/kg/day is sometimes recommended. There is little solid evidence for any of these recommendations, despite some heroic attempts from researchers around the world. Suffice to say that no climber would need as much protein as a competitive weight lifter.