In fact our economy is littered with the detritus of collapsed or dying technology giants. To name just a few there's SGI, Sun, Thinking Machines, DEC and Yahoo.
With the possible exception of DEC none of these companies had any appreciable union penetration. In fact, some failed giants (Zynga and Groupon come to mind) were notorious for being vicious to their employees.
All of these companies are flashes in the pan compared to Eastman, which stayed at the top of the innovation game for generations.
If the salient difference between those companies and Eastman was Eastman's unions, that makes the unions look pretty darn good.
In your examples, for instance, Zynga and Groupon are companies that - as far as I know - did absolutely zero technological innovation; they're known for their business model innovations.
Is it possible the employees could be treated reasonably well without the unions? Is it possible that unions have downsides that might affect a company's health?
If either of those are true, it doesn't seem fair to frame "the HN takeaway" like this.