For anyone who works in architecture, balsa wood is what you use to prototype ideas. 

It is also one of the weakest, most breakable woods.

I'm not sure there's a single bad thing that is analogous, like unemployment. I think the bigger point is, it's scary, and especially AI is volatile, and it's very unclear whether technologies are good in retrospect, for many reasons other than "they centralize power".

A more direct analogy might be, suppose AI does what people hope it does. What happens next? It's unfair to say about the cotton gin, "Imagine the manual labor were replace with a machine" and stop there. Specifically, prices will move and people will respond to those price changes. Generally, the environment will change, but people will adapt their own behavior to those changes.

It's not clear there aren't general principles that can be drawn. For example, any technology that makes it easier to remove clean water will, first order, cause there to be dirty water. Second order, it will probably cause more areas of land to be settled. We aren't sure about all the complex unforeseen consequences, but this seems like a good general rule of thumb. More land settled generally means more people and economic activity.