> I'm not advocating against social norms, but rather specifically about 'etiquette' like how people aren't supposed to wear hats indoors, or that you should end all your sentences with sir or ma'am to be considered polite.

But those etiquette things are also emergent social norms, no different than the others. And they absolutely do change over time. Very few people consider wearing a hat indoors or not ending all your sentences with "sir" or "ma'am" rude anymore, for instance.