To me part of our job has always been about translating garbage/missing specs in something actionnable.
Working with agents don't change this and that's why until PM/business people are able to come up with actual specs, they'll still need their translators.
Furthermore, it's not because the global spec is garbage that you, as a dev, won't come up with clear specs to solve technical issues related to the overall feature asked by stakeholders.
One funny thing I see though, is in the AI presentations done to non-technical people, the advice: "be as thorough as possible when describing what you except the agent to solve!". And I'm like: "yeah, that's what devs have been asking for since forever...".
Just because you haven't or you work in a particular way, doesn't mean everyone does things the same way.
Likewise, on your last point, just because someone is using AI in their work, doesn't mean they don't have hard skills and know-how. Author of this article Mitchell is a great example of that - someone who proved to be able to produce great software and, when talking about individuals who made a dent in the industry, definitely had/has an impactful career.