The problem is a constant fight against gravity. You’ve still got to pump the water effectively to the top of the building every day. And there’s still the issue of getting sunlight to the plants.
The question really becomes whether it’s more economical to just use traditional irrigation techniques upstream and ship the produce in vs converting a skyscraper into a very inefficient farm space.
You would turn down free bread sticks and $7M? At least eat some bread sticks.