Why always the same races?
Open a fantasy work and three races are almost always present: elves, dwarves, orcs. Western high fantasy or Korean web novel, they show up in the same slots as if by agreement.
I used to take it for granted; after enough works I got curious about why. Here is the lineage as one reader sees it.
The root — the template Tolkien laid down
Today's race template comes, almost wholesale, from The Lord of the Rings. Tolkien took the fairies, dwarves, and goblins scattered through myth and gave each a full language, history, and temperament.
Images that had been loose were bundled into one set, and nearly every later work borrows that set. You can't skip Tolkien when talking about races.
Elves — superior, yet fading
The core mood of elves is superiority and decline at once. More beautiful, longer-lived, gifted in magic and the bow — yet often drawn as a people past their prime.
That note of fading nobility makes elves more than 'pointy-eared pretty folk.' As humans rise, elves withdraw — and that melancholy is their appeal.
Dwarves — craft and stubbornness
Dwarves are nearly the opposite axis: underground and in mountains, short and sturdy, the people of the forge and the mine, heavy on honor and pride, weak for gold and gems.
Their frequent feud with elves is also Tolkien's doing; the contrast of graceful forest folk against rough earth folk sharpens both at once.
Orcs — from enemy to a people
Orcs started differently. For Tolkien they were nearly faceless enemies, dark mooks to be cut down.
Later works gave orcs society, honor, and tribal culture, promoting them to a people. Now they often carry their own values, and orcs joining the hero's side is common.
Record of Lodoss War — races as game language
Record of Lodoss War is close to a translation of Tolkien's race set into the language of tabletop RPGs — elves and dwarves taking a party slot, race tied to class and role.
Much of the race imagery Japanese and Korean fantasy absorbed is, I think, not the Tolkien original but the version filtered through Lodoss.
Dragon Raja — races that think in Korean
In Korea, Dragon Raja set a new axis for race writing, making elves, dark elves, and orcs act in the cadence and thought of Korean itself, not translationese.
Even the same elf speaks on a different beat in Tolkien and in Dragon Raja. It shows race is also a matter of language, beyond worldbuilding.
My take — races are a shortcut into a world
These three became standard because they are a promise the reader grasps without explanation: elves bring grace and magic, dwarves craft and stubbornness, orcs wildness and tribe.
For the author it is a shortcut to set a mood in one word. Sorting the races here, what struck me is that a race is a shared language between a world and its readers.
To read fantasy more closely, watch whether a work follows these three standards or bends them — the author's signature shows up fast.