mrfuji3, Wormerine, Gray Ghost, I would be more inclined to agree if the games were self-contained. But they aren't, and I said BG3 is a sequel (contentious, I know, but there are hints even without touching on the datamined content) and taking place in an established setting purposefully. For better or worse, BG1 and 2 were at least in part canonized, so they are now one piece of the history of Forgotten Realms. They are not their own thing, they are a part of the larger whole, like novels, comic books, and other supplemental media. And just like I don't think it's unreasobale of, for example, a novel taking place in Waterdeep to expect its readers to have some basic knowledge of what Waterdeep is, I don't think it's unreasonable of BG3 to expect its players to have some basic knowledge of its setting either.
For the record, I'm not styling myself as some sort of lore expert here, I've had to look things up over the course of playing EA. I just don't believe it's a fault with the game that I had to.
I also disagree that only videogames can age poorly. This is something inherent to every living medium. Both language and literary conventions change over time, and new filmmaking techniques are being constantly developed as well. Just as with videogames, these changes can make it hard to come back to older works. Regardless, once again, I don't believe it's a fault with the third game if people can't be bothered to play the first two.
What is reasonable in my opinion is explaining whatever homebrew changes Larian makes to the existing lore (such as the changes they made to ceremorphosis), and things an average Baldurian would not know. On principle, more expository dialogue is not bad either, but as was pointed out, when everyone is willing and able to give a lecture on whatever part of the setting they're connected to, it can come off very unnatural. It's something that has to be utilized with care.
