Not really. If every Amazon warehouse organized, you would still need Walmart, Target, etc warehouse workers to organize to achieve something comparable. And in the U.S., they still wouldn’t have the same bargaining power because solidarity strikes and similar tactics are illegal. But I agree that labor laws are not deterministic, as the teacher strikes in red states have recently demonstrated.
We’ll also have to see what extent states will further block organizing activities if this starts gaining traction in places like Alabama. Given things like the extremely violent police response to protests, I’d wager “pretty far.”
Not gonna look up the actual figures, but safe to assume that amazon US is bigger than all retail (certainly online retail) in the netherlands, belgium or whatnot.
In fact my 1980-2020 pendulum analogy doesn't work for (eg) Germany or France like it does for the UK or US. In a lot of western europe, there wasn't the same sharp de-unionisation. So, unions exist and their role is well understood. They more or less form for a regulatory body for labour by sector. It's stable. I doubt amazon themselves are concerned about these. Not much uncertainty here.
Interestingly enough, shop-level organization at amazon scale gets somewhat similar to sector-wide unions.
In any case, unionization laws aren't deterministic.