why does Chinese or Japanese have symbols? Why does mathematics have symbols? Symbols represent concepts. Once you know what a symbol means you can grok a lot from it. They are limited by using keyboard characters, if the authors had their way, they would have a custom keyboard with custom symbols, but then most people will not be able to use it with any computer, so they stuck to such characters. The idea is notation as a tool of thought. You don't have to think of chunks of words to think of reversing a list. Yet, that's how we often think when we program, we read keywords or list expressions or loops and run the code in our head which slows comprehension.

https://www.eecg.utoronto.ca/~jzhu/csc326/readings/iverson.p... or https://www.jsoftware.com/papers/tot.htm