There might have been enough material not worth cutting for 2 films, but 3 was ridiculous. I'd have to think more about the specifics and reply again, but cutting the obvious non-canon stuff in the Woodland Realm would be a good start.
Well, while the OP implies removing non-canon stuff, some people really like it. Without defining "correct-ish" or "sensible", there really isn't much that isn't an acceptable answer.
That said, Jordan isle rarely explains their replies.
I was thinking during a re-watch how different the trilogy would be without Tauriel and the Lake-Town mythology building. In that, how do they contribute to Bilbo’s adventure and the overall narrative? Would the trilogy become a sequel? Book fans might appreciate that more and I did not mean to besmirch the original Hobbit trilogy or the extended cut, lol.
There is a fan made edit called the hobbit M4 edit. It cuts a lot of crap out (no more she elf, no more ridiculous fight scene) and is the best version of the hobbit I have ever seen!