I believe that the way we represent information is key to understanding. Data points in a list are usually way less insightful than a good graph (emphasis on good).
What I have found is that it's the case in describing system architecture as well.
As you say, you can describe a system in a few paragraphs, explaining the relationship between the main components. However, as paragraphs it can harder to grok, and also harder to write with no ambiguity.
Now, part of what I say above can be seen as personal preference (text vs image), but in practice I have found that when using tools like plantuml or mermaid to make C4 diagrams, the result is easier to use, remember, and update than plaintext.
As you say, you can describe a system in a few paragraphs, explaining the relationship between the main components. However, as paragraphs it can harder to grok, and also harder to write with no ambiguity.
Now, part of what I say above can be seen as personal preference (text vs image), but in practice I have found that when using tools like plantuml or mermaid to make C4 diagrams, the result is easier to use, remember, and update than plaintext.