Please, please, ewerybody calm down.
There are many plotholes in game, yes, but larian will learn on their mistakes and surely come up with something.
If ,after war, there are still great, unexplored forests, Elvenkind probably is hidding there. blaming humans for all evil.
Dvarves could hidden entrance to their halls with illusion magic or using some sort of trick like dwarwes in Arcanum.
Since lizardsmen are giant lizards, humanity hatren of dragonkind could fall on them to, and if in rivellor are still great, hard to explore(for humans) swamps ,then lizards can simply live there ,hiden, waiting for better times.
And many, many more simple explanations.
I really doubt that black ring would manage to exterminate others, elder than humanity, and more powerful races like that(snapping fingers).
