I wasn't making fun of the height thing, I was being serious, there are 3ft tall humans and 8ft tall humans.
I have never said anything about human centric organization in D&D.
What I said is I see very little evidence that people want to play races other than human for any reason other than mechanical bonuses.
Never do I see long involved essays about what it might actually be like to be an Elf, or Dwarf, or any other Non-Human race. Personally I think that a being that lives for hundreds of years would have a completely alien mindset and viewpoint.
Never do I see long involved essays about what the societies of those alien mindsets and viewpoints would be like. How they would go about conducting themselves within the world, especially one populated by other intelligent speaking beings.
Even the Granddaddy of them all, Tolkien, didn't write his books to examine the minds or lives of these beings he created. He wrote those books as allegory about the industrial revolution.
I claim "humans in funny hats" with cause, in that, all the anecdotal evidence I have leads me to believe that in D&D that's all they are. The D&D forums of this site and others is more than enough evidence in my opinion.
I'm telling you you're looking for evidence that wouldn't be where you're looking, or appear in the way that you'd prefer. I have also explained why there are more posts about the gameplay- it's the only thing that's standardized amongst the whole community, and is the thing that requires the most outreach to understand and discuss. The party's story stays at the table, but a DM watching that story get derailed by a mechanic they don't understand needs a forum post or two. Players handle their stories when they play, because it's not practical or particularly beneficial to make a Reddit post about the whole story of the campaign to ask one question.
I know and have addressed that there are 3ft/8ft tall humans. It is not relevant because Humans don't have attributes that parallel the cultures and all of the other racial characteristics of the alternate species.
Good for Tolkien, and I think that's a valid thing to do too. Fantasy races are a tool for the exploration of ideas.
And I refute your claim due to its innate bias. "Humans in funny hats" is really coming across like standard personhood is not achievable by other species on their own. Races in DnD don't act like Humans with minor variation, they act like people, which is a common ground between all DnD Humanoids. I'm saying, if you take "personhood" as the base of everything rather than "Human," that's how every race is just a hat, even Human. No matter what, you're just picking mechanics and lore, looking to pick an experience. It's fine if Human is your default choice for DnD, but that is very much your choice/preference, not some sort of objective norm. From how I've read your comments, it sounds like you're giving preferential treatment to one option for no reason in your evaluation of the Race options.
If a character is deep, then they're no longer a silly hat. A shallow Human is just as much a costume as is a shallow Tabaxi. It's a bad character that's a silly hat, not specifically an imperfect nonhuman race character. To close, playing a silly hat isn't even a bad thing- I'm only saying it because that's the term you're using to rank PCs.