Well, not really. These are directives, not laws. The laws themselves gets passed in each countries courts, and then each infraction will be handled by the courts themselves. Law in general requires there to be space for interpretation as well, as not all cases are the same.
As outlined elsewhere in this submission, it'd be stupid to require Twitter to be able to import Facebook Posts as Tweets, so the directive is not aiming to require that.
But if you instead have two companies who both allow photo upload and to put those photos in a photo gallery, it's not so stupid anymore to require them to be compatible with each other via import/export, as they do exactly the same thing with the same data.
In the end, the goal of the directive is not to force data transfers between all data models in the world. The goal is to force companies to have a export functionality for their users that outputs machine-readable data.
The incentive for being able to import competitors data is already in the nature of doing business. Exporting, not so much, hence we're now getting laws passed to force companies to be more user-friendly.
>Well, not really. These are directives, not laws.
The GDPR is not a Directive, it is a Regulation (the clue is in the name...).
Regulations are law, they have what is known as "direct effect"[0] and apply as-is throughout the EU without having to be written in to domestic law in each member state.
(Directives can also have direct effect in certain circumstances too,[1] although they usually can't confer rights that people can use against non-State entities.)