Why is the world in SOTZ so... unadvanced? compared to ZA
I'm currently reading Never Keep (book 1), I'm about 74% of the way through. So this might get explained somewhere in the next 2 books, but it's bugging me enough that I want someone to just tell me.
In ZA, they have all of the modern technology that we have. Phones, computers, internet, cars, etc. SOTZ clearly takes place after the events of ZA considering that there are statues of the twins in Never Keep, yet there seems to be zero technology and they're writing with quills and ink wells. Why??
Also, bonus points if you can explain/spoil why they have to wait until 21 to have their magic awakened, when I'm pretty sure its awakened at 18 in the world of ZA, even though they're all in Solaria.