Joshua Cohen is a principal at Fat Pencil Studio
Perspective: it’s the way that we all see the world, so it makes sense to draw in perspective when depicting real-world objects. Take for example this elegant diagram of a London subway station, drawn by Italian architect & engineer Renzo Picasso. He chose a perspective view that enables us to see the entire station and immediately understand its scale and connections. Now for comparison, have a look at two axonometric views of the same station:
These line drawings (source: ianvisits.co.uk) are accurate, but more difficult to understand. Why? Because they present an abstract view of reality. In order to “see” the space, our brains have to process and combine information from multiple drawings. For most people, myself included, this is very challenging without being intimately familiar with the actual space. Parallel projection drawings (including plan, elevation, section, and axonometric views) are useful for documentation because they are relatively easy to create and have a consistent scale that can be measured. However, when it comes to sharing the big picture, a perspective drawing is the way to go.