You are missing the point. Of course you can find a 3pp or build your own setting where halflings and other PHB species have as much clout as elves and dwarves. Heck, Eberron does that! But the question is why does WotC include 10 species in the PHB and only routinely use three of them when constructing backstories for their worlds and adventures? Why do 3pp follow in their footsteps more often than not? Why do so many D&D worlds fall back on the Tolkien tropes: isolationist dwarves, elves in decline, halflings hiding in their pastoral niche, orc raiders and everyone else a nomad with no place in the larger world?
Because people aren't as creative as they think they are and if the individual is, there is a lot of pressure to milk the familiar to make a guranteed buck.
Like it would be interesting if someone built a setting where humans, elves, dwarves, halflings, gnomes, orcs, dragonborn, tieflings, and goliaths were all at their heights after centuries of rebuilding from a feindish or undead calamity. The dungeons being the lost cities, strongholds, and caves of the recuperating evils in the far borderlands and unclaimed inner wilds.
The gnomes could be a nations of geniuses hidden in the forests and mountains producing the tech that would eventually bring the world into the next age.
The halflings being he neutral breadbaskets that fuels the armies of internal struggle.
The orcs could be vicius crusaders hoping to clear out the growing evil.
The dwarves splintering due to the lost books on their traditions and overreliance of the memories of the old.