Update- at 16 my kid is finally completely enthralled by Fellowship of The Ring.
Don't force films or books on your kids when they're little.
Ask them.
When they're ready- they'll say so.
And if after trying it's still not for them-
Let it go.
You're raising a child. Not a clone.
Find other stuff to engage in together.
Signed- my kid cannot get into Star Wars and that's perfectly fine
Gandalf falls.
I pass a box of tissues towards my kid.
Kid- "Everyone knows Gandalf dies but comes back."
Hobbits start sobbing.
Kid grabs tissue.
@Shelter Fun fact:
When I first read LOTR as three separate books I cried my heart out at the end of The Two Towers when Shelob got Frodo.