"Unions" in the US are very very very very very different legally than "unions" in EU and other nations, personally i think they are so different we need a different term for them...
The closest we have to a EU style union would be something like SAG, or the other entertainment unions, which often referr to themselves as Guilds.
The employment unions like being formed at amazon are different animals all together which have ALOT of downside for even the workers in them.