Yep but it is: Water+(Renewable)Electricity+Nutrients&Vitamins+CO2 that creates these proteins/food. So it is not actually "out of thin air", and until we do

Yep but it is: Water+(Renewable)Electricity+Nutrients&Vitamins+CO2 that creates these proteins/food. So it is not actually "out of thin air", and until we don't know how much Nutrients & Vitamins are used (and of course how much electricity and water) we have no way to know how "efficient" the process is. I mean, for all we know, it could be needed (intentionally exaggerated) 1 M3 of water, 10 KWh, 15 Kg of Nutrients and Vitamins besides 1 Kg of CO2 to get 1 Kg of food.