Also depends on crop types. Makes sense to do large fields for corn, for example. But being able to grow herbs etc locally where it's consumed, inside cities makes way more sense. This in turn frees up resources tied to growing and transporting such stuff to cities.
There are pros and cons to both but I think you can get richer data for vertically initially to train systems than move on to larger scale horizontal farms. Tough this doesn't mean there are low hanging fruits their either.
That's a good point - the choice of crop will have a large bearing. I don't know if low margin crops like grains could provide an adequate ROI given electricity costs etc, let alone the outlay required to build structures over huge areas.
In my understanding vertical farming is usually a hydrocultural practice (doesn't use soil). That works well for a lot of horticulture, but not so much for broadacre crops.
There are pros and cons to both but I think you can get richer data for vertically initially to train systems than move on to larger scale horizontal farms. Tough this doesn't mean there are low hanging fruits their either.