I would argue that it’s moreso that there are many more specific and clear social rules, but most people don’t know how to explain them, so when asked, they just say “read the room”. As another person said, it might also be a reminder or shorthand of something that you are assumed to already know intuitively.

I think part of the skill is tone, which is kinda dumb since the truth you communicate is basically the same. Even so, something like “I don’t know why I’m alive anymore” might be considered rude while something like “eh” or “not great” or “same as usual” (hopefully that’s not your usual) or even something like “well, I’ve been a bit overwhelmed by current events recently” would generally not be seen as rude. You can still say something that’s true; you just have to soften things. It would be easier if the softening was not necessary, but as people have gotten at earlier, you have more power to change yourself that to change how the rest of the world reacts to things.