As an AI language model, I can provide an answer based on my knowledge and understanding.

Even if AI is capable of writing and debugging code, the design of programming languages is still highly relevant. While AI may be able to generate functional code, it may not necessarily create code that is efficient, maintainable, or optimized for a specific use case.

A good type system and elegant grammar can still be important for creating code that is easy to read, understand, and modify by human developers. Additionally, programming languages often have unique features that can make them better suited for certain tasks, such as Kotlin's conciseness and Java's robustness.

Furthermore, AI-generated code may still require human input and oversight to ensure it meets the necessary requirements and performs as intended. As such, programming language design remains a crucial factor in the development of software, even as AI technology advances.