The UK's ICO also has a good structured summary: https://ico.org.uk/for-organisations/guide-to-the-general-da...
In general I agree with the sentiments in this article. I've probably spent a total of three to four days reading around the GDPR and I don't really see what's special about this law other than it's imposing decent standards on what was in effect a wildly unregulated industry in people's personal data. If you have a broad distrust of any government activity then I suppose any new laws with "fines up to €X" might feel like "I run a small site on a Digital Ocean droplet and I'm at risk of a €2m fine out of the blue." But that doesn't make it true.
All state action is subject to judicial review, where proportionality is a big factor.
It‘s an aspect of due process that is being reviewed and enforced by every court, up to the constitutional courts.
Example: the German criminal code threatens „up to five years“ in prison for theft.
That does not mean that a first-time theft of a not-too-valuable object could get you five years. Impossible. But not written in the statute itself. But even if a court was mad enough to hand out such a sentence, the revision stage would be swift and without any uncertainty.
Actually, it‘s hard to conceive of a first-time theft-offender going to prison, instead of paying a fine or at least having the prison sentence suspended.