Geography, geography, geography. It completely depends on where you live. Remember, climate change doesn’t just mean hot and dry. Some places will get dry, some will get wet. There will be winners and losers.

They do! The water splashes on them and they can happily absorb their food. :)

They get greedy though so the roots need to be maintained just like the rest of the plant.

Sorry but I don't quite understand, mind elaborating a bit more?

Everything is limited in what crops it can grow, if we can maximize the productivity of space in semi urban areas then we can use the other space for crops that best suit it - grains are great for distant rural farms because they store so well, same with potato, etc where you can fill a huge truck and drive into the city once every season but stuff like greens and herbs lose so much after only a few days from being picked so you either need expensive chilling or other processing or a small lorry taking a load every few days which really isn't a great way of doing anything

OP's example is the wrong way to do it as they water plants in soil, there are plenty of hydroponic towers that you can 3d print and what they do is allow you to have hydroponics (growing plants in water) with very little space requirement so that works great in small gardens or appartment balconies.