7. It Will Be A Fun Fantasy Series For The Whole Family
One thing that Narnia already has going for it is the "fun for the whole family" angle that will develop a nice, round fanbase. While Game of Thrones is beloved, one common complaint from fans who have children is that they can't find time to watch it. The Chronicles of Narnia could be a series that the whole family can watch together, without having to compromise on the quality of the storytelling.
At its core, The Chronicles of Narnia is a story about the dangers of power-hungry regimes. This is first presented in the first book, The Magicians Nephew, and they are present all throughout the book series, to the Last Battle. The characters of the story all have their strengths and weaknesses, and they learn and graduate from them as the story progresses. Some characters don't always develop in the way you'd expect either.
Narnia is also just graphic enough that the story feels serious, but not so graphic that you're worried it would scar your children.