Err, variety in a fantasy setting is good and often times exotic races are a chance to explore perspectives that lie outside of the normal human perspective, or just to have something cool that people can enjoy. There are already magic and monsters, and the source material supports monster races as player characters. So while it may take resources to implement, and maybe some manipulation of how the game treats certain things, like adding more meta tags so they don't need record new dialogue for everything, I think it would be well worth it to add more player races, or even just companions.

Goblins would be quicker than implementing say Orcs or Triton because they already have models and facial options, but there would be a need for new dialogue or responses. Though I do think the easiest way to implement everything is to add Meta tags like Goblinoid or Dragonoid so it sorts the response and only certain dialogues needing to consult your specific race. Like a Dragonborn, Lizardman, and Kobold would all have the Dragonoid/Reptilian meta tag. Goblin, Hobgoblin, Bugbears, (maybe Firbolgs?) would have the Goblinoid Meta tag. Yuant-Ti, Tabaxi, Tortles, Shifters, Aarakokra, and Kenku could all have the Beastial tag. Tieflings, Aasimar, and Genasi could all have the planetouched tag.

Though this would not sort out every race it would give players way more options.

Also different people find different things interesting. I personally find non human characters to be a well spring of interesting concepts in DnD and other franchises. While you seem to be of the opinion that Humans are the most interesting. I want the game to hopefully have enough options for players that most everyone can have what interests them character choice wise (within the confines of faerun/5e) without having to resort to mods.