Much as I like the law, I'm sure I saw a headline when it first went live along the lines of "EU's own website about this law violates it", which suggests[0] that perhaps it could have been done better.

That said, I just looked at it, and this is my idea of a well-made popup: https://gdpr.eu/what-is-gdpr/

[0] But for the Betteridge law of headlines and Gell-Mann amnesia