In my opinion a garden is meant to invite nature into your home in a setting that is also comfortable for you.

Also acceptable is to use it to display your collection of rare and exotic plants.

You could also devise a garden for pure aesthetics, arranging hedges and planters in a way that accentuates the architecture of your house.

Or…you could go full boomer route and waste the space on a flat ugly dead zone with no shade or privacy where nothing wants to live.