>>95878307
It is pretty much this, yeah. Though leaning closer to the fading/dying-out than being rare. Yet.

The humans in that setting aren't native to the planet at all, brought there by the gods they worship. But between all the catastrophes, often involving said gods, the decline in worship of them as their real nature is made clear. The rise of other races, including the Sylvari who in any other setting would be the ancient declining people.