[lathyrus_long]

The objections are to vertical farms for grain, not vertical farms in general. Leafy greens are ideal candidates for indoor growing by artificial light, since they need relatively little light and are quickly perishable. The savings in transportation and waste may thus offset the costs of electricity, lights, and other capital equipment. I think even those economics are usually marginal now, and such vertical farms are usually profitable only if they can sell their produce at a premium due to real or perceived better quality (outside unusual locations like the far North). But there's still room for improvement in LED efficiency, automation, etc., so maybe it will cross over.

The economics for grain are much worse--the plants need much more light, and the product is easily dried, stored, and transported. The processing is also highly automated already. Here's an article with some (dismal) numbers:

https://www.pnas.org/doi/10.1073/pnas.2002655117