1) There is no best book for a subject. What suits a class in Elementary Statistics in one place or program might be all wrong for another.
2) There's a lot more to developing texts (or, as you say, curriculum) than people think. Besides a book, there are exercises and answers to the exercises. There are in class slides, perhaps programming components, and the elephant in the room is integration with the most popular LMSs. And all this has to be kept up to date.
It really requires money. At least in the US, I'm unaware of funding.
I'm an Open Text author so I'm sympathetic to your thoughts but it proves to be complex, IMHO