The main value of the lore, IMO, is as game prep tools. And the fact that my players are not FR loremaaters (my wife read a fair shake of the Driz'zt books, but didn't dive deep) makes it more usable for gaming purposes.
I hear that often, but for me its ironically the other way around. Settings with deep and big lore like FR are more overwhelming and are actually slowing down my prep process. Especially if they have a meta plot ongoing. I always fear when a player in a FR adventure wants to know more about something related to FR history. "ok, roll a history check for me" - "NAT 20!!" - "Oh no...."
Thats why I prefer Eberron from a lore perspective, it has no metaplot, the default starting year is always the same since 3.5 and while it has also has complexity, everything is designed open-ended. The Eberron setting asks questions and leaves a lot of mysteries open, that makes it way more adaptable.
I had one large FR campaign where I often had the procedure of:
1) I need some fact of the world so either I flip thousands of pages or frantically google it.
2) If that happens not in prep, but mid-game its not really viable, so I make something up in the moment that sounds reasonable
3) ...
4) Not Profit (I realize what I made up now contradicts something else, so I have to change that other thing to something new, this now contradicts 10 other things etc.)
Luckily my players didn't even read the sword coasts adventurers guide and didn't realized most of my blunder. But it definitely stressed me out and doubled my prep time. I run only prewritten modules in FR now, but these I actually enjoy quite often, because they give me most of the stuff I need to run the game.