One can see multiple confident and very different explanations in these threads. They can't all be correct at the same time. But at least it's people trying to unwrap what's going on and there are good responses and back and forths et.
A lot of it comes down to the mental models of Unions - they're very different depending on the country you work in. A lot of people just can't believe a system with powerful Unions can be a good non-corrupt system for employees and employers.
Very true! And I also think a lot of people doesn’t understand how Sweden/Nordics differ from eg France and assumes unions all across Europe works the same.