As for why new varieties... Personally, I like the trope of introducing different cultures for the same physical race. It's been done before in D&D, but it hasn't been overdone, and there's plenty of room for more variety in the cultures of the core races. Fantasy fiction in general has a tendency towards monocultures for non-human races, and I think it's good to have options away from that.
There's no value in a culture with 0 internal conflict, where everything runs smoothly and resources are literally infinite, and all of that is handwaved with an explanation like "uhh, magic... yeah, magic did it!" Especially in a world like the Forgotten Realms, where not even magocracies have that kind of access to magically conjured resources. Yet, this is what Salvatore did with the Aevendrow.
There's also no value in saying that these massive cultures have always been there, in places that border other civilizations, but that no one ever noticed them for *tens of thousands* of years. Especially because hyper advanced civilizations like the Aevendrow leave deep traces in the environs. Once again, everything is handwaved with "they hide... WITH MAGIC! And they erase memories WITH MAGIC! And they're so awesome that people willingly let their memories be erased!" Because we can't afford giving these civilizations any problem, so even blatant violence must be artificially justified. Moreover, why are they hiding? They have insane mastery over magic, and their numbers are FAR bigger than Menzo (and note that Salvatore dramatically changed the history of the drow in FR, saying that the drow who would become followers of Lolth simply went underground, founded Menzo, and Menzo is the bulk of their numbers).
In short, it's the worst kind of worldbuilding, with 0 thought put into it, and 0 respect for the work done before. It's just an extremely incompetent way to do "representation".
Greetings!
Excellent points, Namie!
Very poor worldbuilding! That is why I think as they have proceeded, they have increasingly fucked up more and more. Think of how divorced from historical principles, resources, geography, and so on they are on so many aspects.
In our own real history, a constant theme emerges, nearly everywhere, amongst all peoples. They are always fighting, always struggling against rivals and enemies, for resources, women, animals, land. Even small, isolated, obscure tribes way the hell up in Siberia, or in central Africa, in the Himmalayas, Tibet, the deepest jungles of Central America or South America. Even small, isolated tribes, experience war, competition, and *conflict*
But somehow, in WOTC fantasy Barney Land, there are races that manage to live in peaceful rainbow harmony and bliss for thousands of years.
Semper Fidelis,
SHARK