This is what I’m here for
A detailed post describing the origins of Tolkien’s orcs and contrast to ogres.
I think orcs have a compelling place still though over ogres. Ogres can be intelligent and crafty. Orcs are dumb bludgeons.
I think having a bunch of dumb instruments of war with one arch villain just works better narratively in most stories.
Ogres just have their territory they want to keep.
Orcs are part of a conspiracy to rule the world with evil.
A hero fighting orcs to save the world is more glamorous than one of fights with local ogres.
My understanding of ogres may be totally off, though.