But I quite vividly remember any mention of that here on HN back then was responded to with "I'm paid great and can easily change jobs why would I want a union?" (with many engineers only thinking of factory worker unions as a model and forgetting that very highly paid and in demand actors also belong to a union).

You negotiate when you're in a position of strength, not while your value is rapidly falling through your fingers.

With AI and a growing population of ex-corporate workers desperate for work breaking up attempts to unionize would be easier than ever.

Of course, the truth is you can have too many middle managers or too few (it really was bad that in 2017, the biggest achievement was "growing headcount"). But fads have a tendency to overcorrect.