There's nothing new to offer in terms of storytelling.
Peter Jackson had done it 20 years ago. So what is Amazon doing with the story right now?
The true magic of Tolkien's world is that his stories begin literally with the creation of the world by God (and he's made it clear that his god is God), with massive things happening long before the events of LOTR. So there are plenty of stories to tell about what happened before the events of LOTR.
By the way, Tolkien's "creation" story is absolutely beautiful. It is basically God singing, and joined by his angels, and the shape of the world is made by the songs they sing. And of course, his Lucifer figure, Morgoth, doesn't like the song God is singing, and wants to sing his own discordant tune....
Anyway, the reason so many Tolkien fans are upset is because there was so much more that could have been done well.
Ignoring Tolkien apparently. The aficionados are more on top of that than am I.