LLMs are by there nature teathered to the human experience, by the second letter. Language. Without language AI can never speak to a human, or a system in that matter. Create any interface you must make it natural so humans can interact with it. The more natural the easier it is to use.

So LLMs are the communicators, they may not do all the tasks themselves, but they are the foundation to communicate with other processes. This can be done by nothing other than something trained entirely to be the best at natural language.