A picture says 1000 words. Robert Jordan : "hold my beer"
25% does feel about right as a target for pruning, that would put it probably at 150-175% of so of LOTR (by words written) and would be a nice size for say a 5 season (max) or 3-4 film adaption.
Problem is, again, fans happy to chop up and change the authors work on stuff they agree with, but cannot accept change they don't.
I am not convinced Robert Jordan would have been any more accepting of someone chopping 75% of his book as needing pruning as he would have been of a little "woke" being added.
In fact I would argue an author may well see the first as a more significant assault on their works, and that its just peoples other prejudices being hidden using changing things as an excuse.
I find it interesting in that I believe if you have read a works you become more invested, drawing some mental pictures and having a richer more detailed world set out.
Unless the adaption is bringing something excellent its going to struggle against that vision.
LOTR with Jackson has someone who instead of brining a version to the screen brought his version, with a very detailed setup of all the things that mattered to him.
His understanding was probably 5x most fans.
I remember Bernard Hill saying just putting the armour on made him feel part of Theoden, with stuff like the imprints on the inside no one else would see.
Thats Jackson getting to create as close to ME as he could, with other peoples money.
I read Silence of the Lambs before the film. I was a bit meh about it, where as everyone else seeing it was raving. I was meh as it dropped stuff, changed stuff etc
Its the same as happens in just about any conversion, that stuff thats written for film/serialisation doesn't suffer from.
Crossing threads but its going to be interesting to see on Harry Potter.
As someone who has never read the books (I am actually waiting for the new audible conversions with something like 100 actors doing them), I didn't have the issue of things having been changed.
I suspect for many people the films are the definitive version of Potter, at least for now.
Potter will be interesting, obviously JKR is still alive and we know has strong views on some things but her views on other stuff that would be considered woke do not seem to be in the public arena.
One other thing thats interesting is she has strong female characters already so thats not lacking, its already more modern than stuff written by old white blokes who only really wrote strong white men as the good guys (JRRT in particular)