[CaptainZapp]

Now you could not use a CLA drafted by a union and instead try to fuck people over with your own contracts.

That would be illegal in Switzerland (not really a business hating commie hell hole). When a collective agreement exists for specific areas it applies to all companies in that area.

That's not to say that dodgy firms don't try to get around it, but if they're caught it it gets expensive and troublesome. And checks (alas, I don't know if sufficiently) are conducted.

[Jommi]

It's not so clear as it's not entirely objective to determine what companies exist in a certain area.

The national mail in Finland is tasked to do letter service, which no other postal company is doing. Letter service is also the most human intensive job there is.