I've been reading some fan theories on Reddit, and so far, while the lore is interesting, there is a lot to do to make it better. First, and obviously the most important, is how vague a lot of lore is. We have to infer information to put together a story, and we all infer different things. That leads to many different variations of the story, and that just weakens the whole universe in general since none of us have a clue of exactly what is going on. Second, is a definitive timeline. In going with the vaguness of the Grimmoire, It would be helpful to get some date/general timeframe of some events. I've seen theories that assume the Collapse was a very quick event and other believe it was over a long period of time. The guardians are immortal, yes, but it's not the first thing most readers would have in mind when reading through the lore. The Battle for Twilight Gap, for example, with so many familiar names in the relevant cards, it feels like it happened very shortly before we come, when it could have happened for centuries. Third, put the lore in game, we'd care about it more if you did. TLDR: Bungie needs to make the lore a lot more detailed and give a timeline. And put it in the game.