Videos come into my YT feed. One was some old interview with Chomsky. It was about language not politics as far as I let it run.
He said the idea of a standard national language is a modern feature. He said that people did not travel much and people in one village might not understand people in a village 20 miles away. I came across this also in discussions about the Russian and Ukrainian languages. The was little standardization and people were mostly illiterate in any language. I would think that Latin in the Roman empire would have been standardized.
There is an individual advantage to knowing some nationwide language. For educational and career advances for example. I only recently learned that in 21 of 22 Russian republics children are taught Russian plus some regional language(s). Apparently the same is true in parts of China.
In eastern Ukraine, the language of education had been parental choice. Some time after the 2014 coup, Kiev took that choice away in areas they controlled. In Crimea now I think the educational language is Russian plus choice of Ukrainian or Crimean Tartar. In Odessa the only option is Ukrainian now. Eli from Russia is a redhead blogger from Perm RU. She was taught Russian and Tartar in school. Her mom is pissed that her Tartar skills have lapsed.
I recall that bilingual education was the cool thing in California years ago. It was the Hispanic parents that ended that as their kids had crappy English skills even after HS. The program was more for the benefit of the higher paid ESL teachers.
