I don't understand how the Hobbit could even be considered for this. It had pretty much everything from the book plus other Tolkien lore. It was not a straight adaptation. If you really think The Hobbit is the worst Page to Screen Adaptation you clearly haven't seen very many movies.
The Hobbit retains enough of its core story
Yes, they made it to Erebor and reclaimed their home. There is far more to Tolkien's work than the core story. It's the spirit of his characters that Peter Jackson constantly misses. If you think Tolkien's work is just about plot, you should reread everything - or just read his notes to understand the author better. It's for reasons like this that he never ever wanted the movie rights to be sold to Disney.
A storyteller pains attention to every last detail - a good one at least. Every detail of the story serves a purpose and nothing is just frivolity. PJ, and Hollywood, gave the characters different personalities in many aspects. They made the movie more...bankable.
Gandalf not knowing that the Necromancer was around until Radagast clued him in to it. This totally diminishes Gandalf as his one of his purposes of being in Middle Earth is for finding and destroying Sauron. He had already been in the Necromancer's dungeons which is when he received Thain's key and map to give to Thorin. Making one of the most important characters inept at his job is a terrible portrayal of character.
That's just one of many unnecessary departures from the essence of the story and its characters.
You're focusing waaaay too much on the first part of my statement and completely ignoring the rest of it.
Yes, I understand that The Hobbit changes many things from the source material, mostly to its detriment but I didn't say it was
perfect or even good, and I'm far from an apologist for the shitshow that are The Hobbit movies, but compared to truly bad adaptations (ie the worst), where entire stories are jettisoned or completely changed, I just don't think that
The Hobbit compares. It's bad, but not the
worst.
Movies like
World War Z,
I Am Legend, and
Starship Troopers (haven't read the book, but popular opinion is that it is very, very different from the movie, which the movie being almost a satire of the book) are awful, awful adaptations with World War Z having so little in common with the book that it's clear they just took the name and threw it on a completely different story.
The Shining and
Reanimator, even though the movies themselves are very good, are still very, very bad adaptations.