I understand that Europe doesn't have many mandatory union arrangements.

In Canada, unions are often shop-wide with no mechanism to opt out, which makes them very sticky and allows them to grow predatory if they can maintain enough corruption or apathy. I'm led to believe that many US states have similar problems, but that's only based on how American unions are portrayed in news and fiction.

And what has that really bought them? The wages are laughable compared to the US where you'd THINK us non-unionized tech workers would be paid minimum wage. And the famous European healthcare and long vacations are more a function of the government than anything the unions have explicitly bargained for.