It’s common in fantasy and sci-fi to have multiple distinct sapient species (races). How did all of yours come about and survive to the present day without any one species becoming dominant while the rest went the way of archaic humans?
My world doesn’t have any moon or stars, so keeping track of seasons is a lot harder. That makes agriculture really hard, so populations are only as big as can be supported by hunting, fishing, and gathering. This means everyone had more time to evolve and develop sapience and cultures. Still, that’s only 5 people species for me, one of which is extinct and another of which is a kind of plant.
There are only two sapient species in the Lonely Galaxy, humans and yinrih. There is a closely related non sapient species to the yinrih, closer even than chimps are to humans, and the question of why the yinrih are sapient and the tree dwellers are not drives a lot of philosophizing on the yinrih’s part. The Atavists in particular resent the burdens of existential dread and moral guilt that come with having a rational soul and wish to return to being irrational animals.