As a player, I’ve played campaigns with only one playable race; I’ve played campaigns with hundreds. I’m OK with either extreme - and all points in between- as long as what’s available makes sense. And by that, I mean their availability or exclusion makes sense within the game world AND the species themselves are reasonably well done mechanically.My question is: does that appeal to you? Do you like a campaign world that has dozens or even hundreds of player option races? If so, why? What's the upside?
As a GM, I usually land somewhere in the middle, with the number of accessible planets and planes being a major factor in the final count.
The upside, for me, is options. Done right, different races give me different ideas about how to play the game.