Can’t even get young people to vote, no chance in hell they would ever become organized enough to form a union. Besides, it shouldn’t fall on our young to protect themselves, that should be the role of leaders and we should apply immense pressure to make them do that.
They are prevented from voting due to age discrimination. There's nothing physical or mental preventing most young people from voting, only cultural and legal.
Of course under 18 can’t vote in the US, I’m just saying that even those over 18 (~25) who can, don’t. They have the means to influence change and they can’t be bothered to do so, therefore how can we expect even less mature youth to organize something as complex as unified labor?
Voters in the US can affect very little change, either by referendum or through very local representation. At the state and national level, both parties are extremely conservative with one of them actively working to roll back progress and neuter elections.
So while we're in a situation where we are voting to preserve democracy, our young people are taught voting is how they affect change, when it doesn't do that in state or federal elections at all.
Currently progress is very slow, and may get overrun either by civil war or the climate crisis impacting populations.
Some labor unions dominate their industries, and make it super uncomfortable to hire non-union.
So it might be possible to unionize child labor, then force employers to only hire union kids, and then make them unaffordable as a means to discourage child labor practices. Kinda like taxing recreational drugs relentlessly to dissuade their use.