Quoting from Edward Snowden: "I intentionally wave away the technical and procedural details of Apple’s system here, some of which are quite clever, because they, like our man in the handsome suit, merely distract from the most pressing fact—the fact that, in just a few weeks, Apple plans to erase the boundary dividing which devices work for you, and which devices work for them."
Reference: https://edwardsnowden.substack.com/p/all-seeing-i
So the details really don't matter as much as the fact that this creates a huge precedent. And, quoting Snowden again, "There is no fundamental technological limit to how far the precedent Apple is establishing can be pushed, meaning the only restraint is Apple’s all-too-flexible company policy, something governments understand all too well." (emphasis mine)
So I might read through that PDF, I might even understand it, but what it can't dissuade me from is a persuasion that yes, governments can and will take advantage of this turn of events, and no, there is no technological or legal barrier that can keep them from doing so once this is in place.