Both Paris and SB were great examples of the terrorists basically not bothering with using encryption, if they had actually used and benefited from encryption we'd be discussing how to get cryptography re-legalized.
I doubt there's even anything on the phone the FBI don't have from other sources. The reason they're using the All Writs Act with this case is because of the publicity of the case so they can point to Apple prioritizing some vague principle most people don't care about over real dead people. Apple's doing a good job making their argument to those who care about said vague principle, but not to the general public.
I think you're underestimating how badly we're going to be taken to the woodshed on this the first time it's opportune. My be it it'll be some cute little girl dies in a Nancy Grace friendly way and the FBI manages to convince the public that "if only we could have broken these messages" etc. It might even be true in that one freak instance, but then we'll have "[cute_little_girl.name]'s Law" which will make sure that such a tragedy never gets exploi.... reported again, by making sure that the government can read messages when they need to. The US market is too large not to capitulate at that point. That bill passes if the voting public can be stirred up against the greedy and aloof tech sector. It doesn't pass if they see the tech sector and its goals as reasonable, and while we should continue trying to educate people on why encryption is good and important for them, you don't change the number of minds we need to change with rational arguments (or again, we'd have won already).
Edit: very interesting link on the mouse jiggler though, thanks for that!