For designers, even without many ideas, methords, or theories, you can still produce a “good enough” design simply through imitaion, practice, and accumulated experience.
But in the age of AI, creating good design requires writing good prompts. And writing good prompts demands a broad range of knowldege, a solid foundation of understanding, and precise language expression. Of course, aesthetics and taste still matter - and these expectations place an even greater challenge on designers beyond their hands-on skills.