It seems likely the vast majority of HN has never been a member of a union themselves given the audience, so the obsession feels like a savior complex IMO.
Yeah, unions accomplished a lot of good things many decades ago. But if you think they haven't morphed over those decades and are still automatically a net positive for all workers, I could probably sell you a bridge.
For my experience at Teamsters, there was zero incentive for employees to actually perform. Everything was done by senority across the board, and you're literally just aging and waiting your turn.
The insurance was good, the wages were average, and the incentive to do better was non-existent. And yes, firing people unless they did something egregious was much, much harder.