I don't know why people are obsessed with the idea of "urban farming" generally, or "vertical farming" specifically. I'm not talking about small scale urban gardening, or restaurants growing things on the roofs, or using empty lots in places which are technically cities but which have had such depopulation that there is massive amounts of unused land (parts of Detroit, for example). I'm talking about the idea that it makes any sense at all to use the most expensive land in the country, using a very expensive cultivation method, to grow things which could be much more sensibly (and cheaply) grown 50 miles away. The idea that you could - or would want to - do this at a scale which would actually reclaim farmland, when in these types of places (the wider orbits) much of the farmland has already been lost to low density sprawl housing, makes it even more absurd. You can fit a lot of people in a nice skyscraper instead of growing a small amount of crops in the most expensive way imaginable (not everybody wants to live in a skyscraper, and I am not telling you to, but you're going to reclaim a lot more land by allow more tall buildings in certain places than you are by growing a few crops in a tower).
And, yes, there might be some reasonable applications of this, like super expensive delicate microgreens for high end restaurants! That isn't going to feed the world or reclaim any land though. They're luxury items. Fine, I guess, but... (and, again, you can probably just put gardens on the roofs).
