In Sweden the unions are the ones who will go to court and negotiate for you because they know that if you go it will set a precedent that exposes everyone else too.
In Sweden you almost have to be part of a union, not in the least because it is right (because they dictate and negotiate your minimum wage, among other things). In the context of the Netherlands this doesn't really apply, except for specific sectors that are overwhelmingly not tech (or tech-adjacent).