Not every place in the world, like Japan, has an abundance of land for farming. It’s also a reality that a lot of arable land is being used for non-agricultural purposes. It’s certainly a useful science to try and master before we have to. I don’t know why going up cannot be done on farms outside. It seems to me that is better than trying to do it inside.
I think that producers of leaf products like lettuce, etc., could be much more cost efficient and use less water and space for a product we like to eat, say Lettuce, and free up land and water for more “useful” produce. There’s not that much nutrition in Lettuce, I don’t think? But with some ranch dressing? I devour it!