Do halflings horde treasure? Are they known for their crafting of magical items? Dig mines deep underground? Create vast cities? Have a subrace that in the past were a primary antagonist? Do they strive to be have lasting impact on others or conquer enemy territories?
The answer to all of these is of course no. Next, how many adventure modules revolve around idyllic pastoral villages? Being the center of, or the excuse for, conflict is not the halfling niche. That doesn't mean they have no role to play in the game.
So I don't really see why "mod with major focus on [insert race]" matters.
And yet, funnily enough, PC halflings are distinctly outsiders in their own culture. After all, PC halflings DO craft magical things, dig mines, create cities, and, I don't know about you, but, my high level PC's generally have a lasting impact on the setting.
It's almost as if halflings as a race are basically there to tell players what their character isn't, rather than what it is. After all, your character probably isn't an idyllic pastoral farmer. Or a cheesemonger or a shop keeper. Might, maybe, be part of the character's background, but, it's not required nor is it particularly more likely than any other background. It's not like every halfling PC must take the Folk Hero background, nor is the Folk Hero background particularly aimed at any race.
So, here we have a race, with very little lore in the game, very little guidance being given to the players for what that race is in the setting and how it interacts with the setting, very little presence in any published adventure and it's one of the four most common races in the game. And you honestly think there's no issue there?