alt Hacker NewsEfficiency is a funny thing to argue here; Plants do a lot more than just produce food for humans. Also, I'll wager that whatever "produced protein" is manufactured will be only edible/palatable with other additives and processes.
It would be cool if we spent more time understanding our soils and all of the things living in them more instead of finding ways to require more artificial energy to sustain our civilization.
If we reduce land use for food production, it's not like that land will turn into a parking lot. Other plants will grow there, hopefully with richer biodiversity than an agricultural monoculture.