Its equally devastating when you're a renowned expert developer at a specific stack that falls out of favor and nobody cares about your skills any longer. This happens relatively often in tech.
The issue in my view isn't that a single tool has become obsolete, it's that there's nothing to retrain to. All the tools have become obsolete and the AI is eating away at the economic value of core human activities. If AI was really good at coding in one language or framework or something I wouldn't give a fuck. It's the difference between a tool and a replacement.
Eh, this analogy really falls flat. The “stack” in this case has existed for hundreds of years, takes at least twenty years to master, and the best people started working with it when they were perhaps seven. It’s a bit different than Rails falling out of fashion.