Are gardens required in every period of time? Probably, it started at the point when humans started building houses and founding villages. I wonder how it was in the time when the human was living in the natural environment.
In my opinion, gardens were required. I think that unlike the present garden, a contact point with nature was considered to the created space referred as "garden" in ancient times. I'm excited by thinking such things.
If you ask for the creator of a garden, if it is not in the notation, the garden owner's name comes out. When there isnﾕt a notation, a famous gardener's name is used freely. We have gardens where the creator ﾔs name is released, but there are also many cases, where they erased the creator's name.
You can't possibly know how to look at a garden through textbooks alone, therefore the only option is self study. Intensive reading of the explanation in guidebooks is important, but the following classifications are also helpful for both ancient and modern garden:

・The garden to reveal power: "Throw yourself before me." When I encounter scenery which only states "Don't you understand this garden?" I want to repel this garden.

・The religious garden: I donﾕt deny religion, but it is impossible to express a view of the world by forming a garden. When the community is satisfied, it is good, but if they want to be the best in Japan, they have to be alert.

・The garden which entrusts itself to the future: There are many experts who were disappointed at this world and express their dreams and ideals in their gardens.

・The garden which makes you think: There are many Zen sect temples which express their philosophy of life and universe through the creation of a garden. Originally, every garden was a space which evoked meditation, but when species were introduced, an expressive face is likely to appear which results in distraction. When you remove the plants in your mind and ask questions to the immobile and silent garden, the garden teaches you the answer. However, the answer is beyond capability, therefore cannot be understood. You must retrace your footsteps.

・The garden as a reduced copy of nature: People who had a strong impression for scenes of landscape from their travels wanted to cherish it and actualize it close to themselves. This evolved the Japanese garden style. This is the most important characteristic of the Japanese garden. By all means, please read the history of the Japanese garden.