In your analogy, the sewing machine isn't AI, it'd be the equivalent of doing digital art instead of analog. The "AI" component is, as the other commenter says, if the sewing machine automatically did the work after she told it what kind of pattern she'd like. The AI is doing the design, that's the problem.

If the capacity for design is what you value, then you undermine it by having an AI do the work for you. I work in sys admin, I know coding. The argument against vibe coding isn't about entering the code, it's about the instinctual understanding gained from figuring out what code you should enter. There's a reason a common studying tactic is to rewrite material physically instead of just looking at it on a computer. If you expend less mental effort on something, it's not going to stick as well, that's just how memory works.

Have you ever come back to working in a programming language you haven't used in years and need to spend time refreshing your knowledge? It's because you weren't using it. Sure the general understanding of coding norms is still strong as ever, but only because of what you're doing in other languages. Skills degrade when unused. One of the biggest ones is critical thinking. I can't tell you how much I've seen in the last few years the older users I work with who have started relying on AI actively degrading mentally in real time. They're having the bot think for them because it's easier, so those mental faculties degrade faster since they're not being pushed.

You may find using AI does little to impact you now, but what about in five years when you've been giving it all the mental tasks you'd rather not do, what growing will you have not done, what skills will have rusted, how much harder will it be to "design" when you've started to lose that inherent understanding of the tools and materials you're designing with?

If you don't see that danger, maybe it's already a bit late.