There used to be: https://en.wikipedia.org/wiki/T%E2%80%93V_distinction#Englis...

It's funny that "thou" seems so formal now.

And it's all because of the King James Bible! They used 'thou' there when talking to God because they wanted it to seem informal and portray him as a friend. It's quite funny how after it fell out of use, it was reinterpreted as the exact opposite, with people being more formal when talking to God.

There is and there isn't. Turning your Northern Alabama up to 11 might not have any impact when in Northern Alabama but sure won't do you any good in front of a SF VC. Likewise if your way of speaking is, ahem, on the "darker and more urban" side.

How many languages have these sub-languages "baked in"?

I don't know about all languages but Spanish, French, German, Portuguese, Italian, and Mandarin all have many formal and informal conjugations of words

Tibetan is very interesting in this way. Standard/Lhasa Tibetan has itself many registers, and then there is Classic Tibetan, Literary Tibetan, and I forget the proper term but there are also secret/esoteric forms specific to e.g. certain Buddhist and Bön teachings

With all due respect, madams and sirs, I beg to differ.

Those are terms of address, and in English you can just avoid them entirely. In other languages you can't say some quite basic things, such as articles, without explicitly choosing a level of formality, which can be awkward.

Not in the country of origin, lol

Edit: England, bitch.