Just for the first one, right? I remember Ian Mckellen had a breakdown on set because he was sitting in front of the table at Bag End with nothing around him but green screen and was struggling without any other actors.
That’s true, but it was a single scene, not the majority of the movie. Almost every scene with hobbits involved forced perspective.
IIRC in The Hobbit films they couldn’t use forced perspective because they were shooting native 3D.