The problem is that you actually can't really model or describe a lot of the things that I do with my specifications using code without just ending up fully writing the low level code. Most languages don't have a type system that actually lets you describe the logic and desired behavior of various parts of the system and which functions should call which other functions and what your concurrency model is and so on without just writing the specific code that does it; in fact, I think the only languages that would allow you to do something like that would have to be like dependently typed languages or languages adjacent to formal methods. This is literally what the point of pseudocode and architecture graphs and so on are for.