I am not saying no small folk or halflings but why are they so common in world-building other than because we are told they should be there?
we could put something better in its place and move it to say a forgotten realms book.
Why would most worlds particularly have elves or dwarves instead of warforged or tieflings except because we've always been told they should be there?
If warforged or tieflings or the flavor of the day are popular, is it mostly because they're new? If elves and dwarves are popular is it omnipresence and momentum?
Are there a lot of threads about who is unreasonable when a DM has a world conception with limited race and class options and, invariably, a player wants to add in another race or class? Is taking out halflings just going to make them the thing folks will want to add into the world that has no place for them (at least in the DMs mind)? Is having players try to justify Halflings to thwart their DM's world conception the best way to get unique takes on the race?