This feels like an outdated worldview that no longer really applies to data. Data can be exfiltrated from the EU in milliseconds and there's nothing that the EU can physically do about it short of setting up a great firewall a la China.

The only thing they can do about it to retain sovereignty is to tell companies they're not allowed to exfiltrate data. But if they can do that successfully, they can also just tell the companies what they're allowed to do with the data wherever it is in the world.