Small scale, the hydroponic system is the ideal solution when - for some reason - dirt farming is ruled out.
Hydroponics provides ANYBODY who has even as little as 10 ft² spare space, to grow almost anything, such as some favorite herbs and/or some fruits such as peppers, tomatoes, cucumbers. However, you do need to set up a system, and that cost money (all depending).
In my case, I have a large garden, but - sadly - it's all shale, and no amount of composting and fertilizing ever got me close to home grown veggies. So I decided to grow hydro. I went for the Ebb&Flow system. My growing containers are placed on top a bucket containing the nutrient. About 3 - 4 times a day a small pump pushes the water up into the container for about 15 minutes, then stops to let the water run back into the bucket. The whole system is DIY.
I grow parsley, celery, thyme, dill, tomatoes, cucumbers and spinach.

Thanks for the reply! What motivated you to make Ebb&Flow, and also, do you remember the variety spinach that worked (I can never get these to sprout).

Ease of operation and reliability. I went for it straight away based on my research, but I did try out a few other methods on a smaller scale, such as:
Passive wick systems: Herbs do well on them, but generally the wicks don't transport enough water for veggies.
Deep Water Culture (DWC): Works well, but requires a separate seedling stage. You also can't get cheap netpots in my country.
Nutrient Film Technique (NFT): Same as DWC
Drip to waste: Useless! The drips kept blocking no matter what I tried. Gave up on that.

With Ebb&Flow you can plant the seeds(lings) directly into their final containers. That saves space and labour. It's also easy to construct yourself (DIY). All you need to buy are small water feature pumps and some suitable buckets, etc. You can also use some innovative media such as pea gravel, river sand, saw dust & wood shavings.

Sorry, forgot . .
The spinach is actually Swiss chard. Can't grow the real stuff in our climate.