You’re asking about a pretty tough problem, and I don’t have the silver bullet for that one. However, I do have some tools that might help you out a bit. None of these tools are 100% reliable, so take everything with a grain of salt.
When I have a lot of text to go through, I just dump all of it on chatGPT or Bing and ask for a summary. It’s a language model after all, so it should be pretty good at this sort of thing. A horse won’t plow a field all by itself, but if you’re there to steer it, it will get the job done faster than you would.
When I’m looking for a good book to read, I’ll usually use the reviews of goodreads. Just skip all the 5-star reviews, because they are usually written by people who aren’t competent at reviewing books. Take all the the 1-4 star reviews dump them on your favorite LLM and let it look for frequently reoccurring complaints.