I love it because it is akin to studying ancient texts. Commercial publishers put out highly curated versions of the popular classics that rewrite or reconstruct most of it. But studying the actual text, or as close as one can, in archeology books that contextualize the texts and annotate what we know and what we assume, and the different sources of each piece. It is so fascinating how much is like detective work. Lots of things are incomplete or only make sense by using assumptions from elsewhere in historical evidence. That's my approach to the Silmarillion.