Because good benefits and working conditions are fleeting without the power of collective bargaining behind it. Without a union, employees are depending entirely on the goodwill of their employers.
This. Amazon became a ripe unionization target because they get noticeable productivity per worker. Its rates are closer to manufacturing compared to typical retail and the other prevalent, low-income jobs.
With Amazon's massive investment in robotics and other opportunities for automation, they think they can become exponentially more efficient. At that point, a non-unionized workforce will lose that goodwill and be slashed into a fraction of its current size.
In an ideal world unions shouldn't have to be anti-automation, because people should have access to other sources of income (yes I mean income, not specifically employment) if they lose their jobs. This way we aren't holding back technological progress to protect people from poverty.
I have no idea what that ideal world looks like, maybe it's not possible. But I do feel uncomfortable with the idea that automation is somehow inherently anti-worker with no opportunity for reconciliation.
With Amazon's massive investment in robotics and other opportunities for automation, they think they can become exponentially more efficient. At that point, a non-unionized workforce will lose that goodwill and be slashed into a fraction of its current size.