wait so what does past pure looks and stats determine what race players select and dms want to world build with?
I'm not sure exactly what you're asking, but I'll try to answer what I look for in a species.
1.) Aesthetics. Does the race look cool? This is why you see favorites like elves (beautiful), tieflings, dragonborn and animal-folk all very popular. Halflings are traditionally small and either childlike or barefoot pudgy types, and really don't fire up that "cool" aesthetic when you have dark elves and demon-kin on your team.
2.) Do they have a niche in the world? So many races fall short in this category its criminal. Dwarves and elves always find a home in the mountains and forests and have ancient empires to create dungeons and such from, but everyone else exists in the shadows. Halfling lands, if they have a place at all, are some pastoral paradises where nothing happens. Gnomes split between dwarves and elves like the two have joint custody. Orcs get caves if they are allowed anything. Tieflings, dragonborn, and goliaths kinda exist (outside of Nerath, the only place to give them their own fallen empires).
3.) Do they have an interesting mechanical element: Do they fly? Breathe water? Have spells? Teleport? Resistant to an element? Have claws, fangs, shells, or tails? Unfortunately, the old "demihuman" races all end up on the short end of this stick because they are basically human with an exaggerated characteristic (and three of them got "short" as a defining trait). As such, players will gravitate to races that have a unique gimmick.
Dwarves get by on having a solid place in the world. Elves get aesthetics and niche (and with the proper subrace, mechanics). Dragonborn have aesthetics and somewhat mechanics, tieflings have both in spades. Gnomes kinda have mechanics (depending on the edition) and halflings reall drew the short straw (pun intended) as "lucky" isn't really a lot to hang your hat on.