One example that comes to mind is the "string by default" approach of HTML, Markdown, etc. Another example would be "no strings at all", like WebAssembly with

One example that comes to mind is the "string by default" approach of HTML, Markdown, etc. Another example would be "no strings at all", like WebAssembly with only integers and floats. I'd say neither fits the description of enabling expressive data structures or being more readable.