Whether it’s a net positive or negative force is basically too complex a question to answer without resorting to an overarching unfalsifiable ideology like neoliberalism or socialism.
However, rule of law, predictability, and stability are unambiguously good for everyone. Attacking businesses or people on pretexts unrelated to the underlying reason a politician wants to hurt them is a hallmark of corrupt countries.
If we decide as a society to legislate stronger union protections then sure, enforce them against Amazon (and everyone else), but it seems bad for that to motivate selectively enforcing unrelated antitrust laws.