We don't speak the same languages
the reason humans need tribes is because otherwise they encounter others on their side in the wild and they attack each other
this was true 10,000 years ago and it is true today. You can see this happening on twitter
https://x.com/DefenderOfBasic/status/1850913920409550974
Here's a real life example of translating from one culture to another, something that sounds completely unintelligible until you learn to decode it:
https://x.com/AskYatharth/status/1850069618821562795
This is essentially the basic premise of Anatomy of an Internet Argument, showing how to do this.