You: they should be diplomats.
My answer: In my campaign the Renai (nomadic trader halflings) do this to a limited extent by spreading news of he world and delivering letters and messages. But true diplomats are very political and requires a lot of force of personality, something halflings are not known for. Being likeable doesn't really make you a diplomat.
I don't know why your campaign matters for changing them in the PHB for the future.
"Political" is an odd term. Not in that you are using it, but because of how it works in practice. The guy who says "both sides have good points here, and we must try and find where everyone can at least agree" is being political. Politics is a game of compromise, and I think Halflings could fill that role quite well. I'm picturing the old Grandmother with her cup of tea, making sure that the two young people sitting at the table stay civil and communicate properly.
And, I don't think it would require much of a shift to make halflings have more force of personality. After all, this idea of being likable and building bridges between people is the entire reason for the "diplomat" flavor of Half-Elves, so there is good precedence for that direction.
You: they should be lore keepers.
My answer: that's quite out of left field. I don't see them caring about libraries of knowledge, nor is there any connection to their roots or lore.
I'd take it as an expansion of their love for stories. In older times stories, epic poems, plays and songs were the primary method of saving knowledge. And halflings already love stories, I'd just expand and formalize it. Maybe they are the Bard race, traveling around, making friends, swapping tales, that feels like something a halfling could easily do and still be a halfling, and with just a bit of a push to have them purposefully collecting information and traditions of remembering and writing, it could fit in rather well I think.
It just currently is not how they are presented.
You: Better origin story.
My answer: I've never met anyone that really cared about the origin story of a race. Is there even an origin story for humans? Or races other than dwarf and elf? I also think this should be setting specific. I mean mine would probably start with Ginnungagap for example, I doubt many others would.
sigh, as I have said over a dozen times, humans are the exception. Because saying "this is the truth of human origins" has some sticky implications. And yes, there are a lot of races with origin stories. Dwarves, Elves, Gnomes, Firbolg and Goliath (tied into giant lore), lizardfolk. Some of them are more vague or could be seen as setting specific, some of them are about massive changes into their current selves, like the Kenku, Nagpa, and Yuan-Ti, but most races have an origin of some sort. And it is weird that halflings don't.
You: characterize a question as an accusation
My answer: if you want to twist a question into something it's not I can't help you.
When you ask a question that has been answered already, multiple times, how else am I supposed to take it? Honestly. I had said multiple times before that post that those attributes were not what I was asking for, and then you came in and asked what could we possibly want? These attributes? The ones I had specifically already answered and said I did not want?
The only two conclusions I could come to was that you had not read my posts enough to understand my position, or you were once more accusing me of the same thing that a bunch of other posters had accused me of. And those were accusatory questions. You could have simply asked "what would it take for halflings to be interesting?" and that wouldn't have been an accusation, but following it up like so "What would it take for halflings to be interesting? Them to be bloodthirsty savages?" is an accusation.
You: halflings don't "connect"
My answer: I don't even know what this means. Every race is just some extreme of humanity with minor set dressing. Elves are back-to-nature hippies (sort of), dwarves are nose-to-the-grindstone work hard play hard types and so on. I explained how they fit in to my world just fine. This is where it's confusing, you don't want them to be overly aggressive or political, but for better or worse that's largely what history records as being important.
You are conflating "extreme form of humanity" with what I said, and that's not the way I mean this. You are also talking about what history records, but we certainly recorded more than politics and war.
What I mean is pretty simple. The way a halfling shire is presented, they seem like an idyllic demi-plane floating in some out of phase place only marginally connected to the world around them. Putting a halfling shire within 10 miles of a human or elf or dwarf border means nothing. That Shire could be anywhere, but as presented from the books and people's arguments, it would be the exact same, and it changes nothing about the world around it by being placed there
We've actually got some posters who are saying that the entire point of Halflings is that they don't matter. But, that is the problem. A halfling shire doesn't affect the world around it in any noticeable way. It doesn't provide anything beyond being a pastoral farmland full of people living at ease and enjoying their daily life. And there is nothing wrong with a village like that, full of common people living their lives... but that is EVERY halfling shire. Dwarves, Elves and humans have those villages and areas too of people living their ordinary lives, but they also have more. Halflings don't have anything more, and presenting them as they are meant to be presented makes them seem like they aren't even aware of the outside world and makes them feel disconnected.
You: halflings are just short people, children that ignore the world
My answer: many of the races live in small communities that have little to do with the outside world. For example firbolgs also ignore the outside world and just want to live in their forest homes. It's also well documented that people find short people less convincing and less attractive, I think this is a common prejudice people have whether conscious or not.
I don't care about your well-documented prejudice. That isn't the point. The trait "short" isn't enough for a race. Goblins, Kobolds, and Gnomes all have a lot more going for them, and are also short races. I know you think the majority of us are against short people, but that doesn't hold water in this case. I'm fine with all of the other short races. I'm just saying being short isn't enough.
And, there is a massive difference between Firbolg and Halflings. The PHB tells us that halflings are protected by humans. Firbolg protect themselves. They don't want to go out and interact with people beyond their forest, but they do keep an eye on those settlements, and if someone makes a move on them, they will react themselves. And yes, I know the inevitable comeback that halflings fight in defense of their homes... if they have to. But, the PHB states it clear as day on page 27 regarding the relationship between halflings and humans "And by protecting their own lands, they [humans] protect us as well."
There is this undercurrent with halfling lore and presentation that they need protection from other races. Something that isn't the case with any other race in the game.
You: lucky doesn't show up
My answer: First, it's not up to the DM to dictate how a PC acts. Second, lucky is easy. A 1 that becomes a hit means you were aiming for the right knee of a foe and totally whiff only to land a solid hit on the left inner thigh and so on. Personally I leave it up to the player to describe if they want.
So, you basically are saying to ignore one of their most iconic racial themes. Because, again, you keep offering a solution to the wrong part of the problem. And yet still seem to think that this is a personal issue with me. At least, if I go by your last post on the matter.
Because no one seems to have an answer to show how a halfling is lucky if they don't roll a 1.
You: brave doesn't show up
Halflings are significantly less likely to be affected by anything that frightens, the proof is in the pudding so to speak. I think it's mostly up to the player though. I describe the difference between bravery and courage as the following. Bravery is doing what needs to be done because you have no fear, courage is doing what needs to be done despite your fear.
I know what bravery and courage are. Again, that isn't the issue. I understand what the words mean. But again, you solution is that I have to ignore it and hope the player can figure something out. And yet again, you seemed flabbergasted that I can't think of a good way to portray it in the game. I would think that "just make the player do it for you" is clearly a bad answer.
You: I don't like their traits
My answer: that's the core of their identity, the aspect of humanity that they represent. Every race represents some aspect of humanity, are dwarves bad because some people are gruff and hard working? It's not wrong to not like it, but it's just an opinion. One a lot of people don't share.
In conclusion? All I can say is that you can't please everyone. I have no clue how you would change halflings other than the diplomat and lore keeper thing. I personally don't see that making sense as a base for the race.
Why don't you see that as making sense for a base race?