Shemeska
Adventurer
Wasn't that the case with modrons, notwithstanding all their “coolness”? Had there been as many LN extraplanars as there were celestials and fiends, maybe modrons wouldn’t look so much like the inevitable (pun intended) LN race.
Grouping tanar'ri as a group of demons, then taking the other subtypes of demons in the Abyss, I could probably come very close to matching that with outsider groups native to Mechanus, and match of exceed the natives of Mount Celestia, Elysium, and Arcadia.
Mind you, I find filler races less irritating than the misuse of mythological concepts in dnd’s cosmology like Maruts as the stoic embodiments of law... ugh, especially when Indra dwells in Limbo and don’t get me started on “Limbo” and “Nirvana”…
I don't pretend to know any of the Hindu mythology that vaguely backs them, but the Maruts of D&D were created by Rudra, who did live in Mechanus. Nirvana hasn't been used as a plane's name since 1e.