I don't think it makes any part harder. What it does do is expose what people have ignored their whole career: the hard part. The last 15 years of software development has been 'human vibe coding'; copy+pasting snippets from SO without understanding them, no planning, constant rearchitecting, shipping code to prod as long as it runs on your laptop. Now that the AI is doing it, suddenly people want to plan their work and enforce tests? Seems like a win-win to me. Even if it slows down development, that would be a win, because the result is enforcement of better quality.