Vertical farming, the best solution to support an ever growing population or just a scam?
IMHO it has a lot of potential but not being able to grow grains really is something that should be tackled sooner rather than later. But I could see this being used by self sustaining communities to provide lots of food while using very little space. And it's technically more environmentally friendly than just using vast stretches of land to produce the same amount of food.
Isn't the entire point that it scales?
Exactly, so that it doesn't scale is a negative. OP did a good job of listing the type of niche where it can maybe work despite not scaling.