I should have waited and responded to you once but I didn't think I'd respond to your response here
They don't. Halflings are small folk, they don't need epic cosmological histories.
Stop. Who said anything about epic? They don't need an epic cosmological history. They need
ANY cosmological history. My first post was me literally realizing I couldn't remember the origins of halflings, and then when I looked... they don't have one. I guess they were found one day by the goddess... and that's it. They already existed and "were timid wanderers, scraping out a meager existence."
That's it. The only other race of people I can think of from the PHB that just... appears like this are the Humans. Which, again, special circumstance. Maybe the dragonborn, but they have a few different origin myths depending on the setting. And with a bit of research I can find the origins of most major races in DnD, so the lack of halfling lore is glaring.
And in my settings most species don't have such either. Sure, there is history and mythology like in real world and different cultures have their own stories, but ultimately it rarely matters how dwarves were made and it matters even less whether the dwarven beliefs of their origins are true. Now of course in any world I make I try to give each species a well defined thematic and ecological place, but that varies from a setting to setting.
It gives a sense of realism. Every person asks eventually, "where do we come from" it is one of the biggest questions of existence. Things have an origin point, and when the gods who created things are directly there to tell people they made them... it is odd to not have at least a story about where they came from. Especially for a race who supposedly enjoys stories so much.
Also one thing a lot of people have noted as a negative is the halflings living among humans in many settings. That actually is one cool element of them to me. There are no halfling lands, there are halfling communities among other species. And the idea of half the human sized creatures just living along humans is funny to me (in a good way) Halflings living on the human attics, more affluent ones just dividing human house's floors into two smaller ones. Humans and halflings having sort of symbiotic relation ship is pretty unique and it is different than what most other species do. I guess goblinoids living in mixed group of bugbears, hobgoblins and goblins come to closest, but it tends not resonate so well as we're not so familiar with hobgobling lives than we're with human lives. Often I like to add ogres in this human/halfling mix to get a third group in the symbiosis.
I think it would be a cooler symbiotic relationship if halflings were so human. If they were decidely unusual and inhuman, then it would be a far cooler relationship. As it is... it is just humans living with humans, but some of the humans have special needs.
My current setting has no normal halflings as in it the halflings and elves are combined into one small kendery-elfin species called the eldri or elflings. But I was thinking another setting recently which would have higher tech level. In it the halflings would have this symbiotic relationship with humans (or perhaps even parasitic in a sense, if you ask the humans.) The halflings live among humans as overlooked underclass, as the humans generally have the same amount of respect and understanding for them than many posters in this thread. So they just live on the fringes of the society, being scrap collectors, low-level workers, swindlers and dealers, gangers living in severs etc. Humans generally don't pay much attention to them, and they basically just run their own small communes in the shadows of the human cities and villages. This also gives them freedom to engage in all sort of underhanded and shady stuff without being noticed.
I'll note, you have taken Halflings and made them small elves or basically gnomes. And then you took another setting and basically made goblins and made them less traditionally ugly and called them halflings.
Like... seriously. In that high tech setting you are literally describing a VERY traditional sci-fantasy trope of goblins.