That's like arguing hydroponics will never be more cosy-efficient than a greenhouse which will never be more cost-efficient than a garden. Because the former ea

That's like arguing hydroponics will never be more cosy-efficient than a greenhouse which will never be more cost-efficient than a garden. Because the former each uses more energy and speciality materials while the latter each can offer a more integrated ecosystem. I'd you see it purely economically, the question is just a matter of inputs vs outputs. If you can take grain and circumvent the inefficiencies of a chicken (gets sick, grows feathers, grows bones, produces excrement, ...) and instead get the same nutrients more directly to produce meat of course it's more efficient. The question is just how much else is needed - energy, space, cost of producing the initial materials, harvesting time, ... Not to mention moral implications that a vegetarian might care about or practical elements (can you grow it with flavour?; do you need less space?; ...). That said, obviously its not going to touch the ubiquity of chickens anytime soon - eapecially in poorer countries - as the tech is high cost while you can start your own chicken coop with two eggs or chicka. But heated greenhouses are also not replacing tomato fields and yet they have a huge role in some regions of the world.