This was many years ago, is my recollection flawed?
It's true that the first 50 pages or so are pretty much just worldbuilding, mainly focusing on the mythology behind the creation of the world (Arda) by Iluvatar and the various demigods. After that, you start getting into the details of what the elves did upon waking up as the first quasi-"mortal" inhabitants of Arda, and the subsequent eras of history. Some of it is painted in broad strokes, but there are plenty of chapters that zoom in on specific characters and their heroic and evil deeds, personal conflicts, betrayals, hubris and other tragic flaws, etc.
Sure, the style of the prose is a bit dry, but there's plenty of drama to be had in the story.
Wikipedia has a pretty good summary of the overall plot: https://en.wikipedia.org/wiki/The_Silmarillion#Synopsis
The Halo story bible is an exception which has seen parts released: https://www.halopedia.org/Halo_Story_Bible
A portion of the story bible for ATLA was leaked: https://www.reddit.com/r/TheLastAirbender/comments/aj0mfp/th...
You might as well leave it be.
Some parts are more like a traditional narrative: the story of Beren and Luthien, and Turin Turumbar.
If you didn't find it enjoyable to read before you might not change your mind at a second reading, but if it really was a long time ago it's possible your perspective may be different.
Then you get into the elf family trees and their migrations. Its really dry. But it really helps understand the motivations of individuals in the rest of the book and the other books. There are some diagrams in the back to help you plow through it.
Then there are the accounts of both individuals and nations/races. They are more like greek tragedy than anything else. Though sometimes it doesn't even seem like there needs to be a flaw to bring down the fall. It is like binging all of Breaking Bad at once. Not going to leave you smiling, but that doesn't mean it isn't art.
It’s also not a great way to characterize the Second Age, since both a portion of the good and a vital portion of the evil sides in the conflict survive and both are very greatly diminished, but I don’t think the writings about the Second Age were really central to that work. That’s why the show (which I haven’t seen yet) seemed like perhaps not a terrible idea to me. There’s not much legacy there to tarnish.