Tales and Chronicles
Jewel of the North, formerly know as vincegetorix
That's also my idea. The elves would have fled to the Feywild and be more Eladrins now. The dwarves would all be duergars and derros now, having been forgotten by their gods after being enslaved by the mind flayers and other slimy stuff. Gnomes disappeared from being ''forgotten too much'', sadly most people dont even remember that they once existed.For my part, I prefer Faerun with its wondrous variety of peoples. That being said, were I to make Faerun human-only, I would say that the dwarves and elves and whatnot were a thing once, but have disappeared for one reason or another. The setting is already filled with ruins and remnants of their ancient civilizations.
Anyway, its just a weird thought I had.
Next step: What would be the Realms if all human nations were replaced my non-human nations!
Cormyr, nation of Elves Dragon-slayer, with the Dalelands = the Shire?
Eltugard, home of the Hellriders, an army of Centaur Paladins?
Waterdeep, cosmopolitan cities of 1000 races? (not much change there)
Icewind Dale, halfling and gnomish frontiers?
Chult, tropical paradise, home to albino dwarves, tabaxi and sentient undeads?