The thing is that in Sweden these collective agreements are regulating things that other countries regulate by law.
It is part of Swedish culture and worked so far, because employers held up their side too. This is one of the reasons why Sweden is working so well in many aspects. Employers and employees have a mutual understanding of respect and working with each other. But because of that many things arent codified into law, because noone ever thought they’d have to.
So they have much more to lose than in other European countries, where it is “only” about wages and benefits.