The language that became standard French was one dialogue among many in the “ Langues d'oïl”, a language said that had evolved from vulgar Latin. They were so named because the word for yes was “ oïl", which over time has become “oui”. These dial wax covered roughly what is northern and northwestern France today.
In 1789 people throughout this region would have spoken heavily accented dialects of this language. “Standard” French would have been used in the capital and the area around it, and was also the official language of the court and legal proceedings, having replaced Latin in the 16th century. The educated population would have been able to communicate in standard French.
Southern half of France would have had a large population of “ langue d'oc” / Occitan speakers. This was another widespread set of dialect group together because the word for US was some varioairon of “oc”, which was derived from the Latin “hoc”. Again educated people and government officials would have been able to communicate in standard French.
All of these dialects were fully functioning. Every day language is for the people that spoke them. I have the center of political power been elsewhere, then, one of these other dialects from the north or south could have developed into the standard national language. The political power, and the accumulated cultural power, happened to be centered in Paris. By cultural power, I mean, the bulk of courtly poems and histories and other literary works, as well as scholarly works, tended to be written in what became standard French.
In addition, different bits and pieces of what today make up modern France had some languages spoken in numbers, much larger than they are today Breton, German dialects like Alsatian, Corsican, Basque.
The driving force behind French standardization was originally the simple power of the court, and its ability to decree I. The 16th century that French, as spoken in the capital, was the official language for law in education. Knowing standard French, and speaking, it properly became important tools for political and social advancement.
In 1789 you would still have stop had millions of average people speaking a local dialect, including varieties of Occitan. Republican and then Imperial France, as with so many other aspects of French, life and culture, made an attempt to rationalize and standardize the French language. Even so, it took a protracted effort by the French bureaucracy to try to stamp out Occitan. It was for bidden in schools and both children and adults for ashamed for using it
Today, some of these small languages are undergoing a revival. As always, there’s a risk that an insufficient number of true native speakers will cause the language to mutate into a curiosity or die out entirely.
I don’t have as much information on other countries, but I do know that a similar diversity of dialect existed in Italy, and in Spain both countries went through processes of language, standardization, and often used some of the same tools of coercion and shame to replace the dialects with “good” languages.
I know that in Spain, there has been definite pushback from, for example, Catalan speakers, who maintain the value and having their own language remain, and have a body of literature, which helps support that effort.
Keep in mind that the distinction between a dialect and a separate language is often very subjective, based on political power, and sometimes based on the fact that we know how the story plays out. And it’s a lot easier to describe Norman French as a dialect if you know that it goes on to be somewhat overwhelmed by standard French.
What is true of France, as cited by Hobsbawm, is equally true of all of the major national European languages at some point in their linguistic and historical development, including of English. What’s more, regional variants and social stratifications of language persist everywhere to this day. Here is an article about the modern Italian that is spoken at one place in Italy.
https://anthrosource.onlinelibrary.wiley.com/doi/abs/10.1111/j.1556-5823.2008.00003.x
Two exceptional cases help to prove the rule: English and modern Hebrew! What is true of both English and Hebrew is that their development was influenced heavily at a critical point by a small but highly literate and scholarly minority.
While English is certainly not a completely standardized language, modern English developed contemporaneously with the establishment of the Church of England. The Church of England was the reaction of King Henry VIII to the refusal of the Catholic Church, then dominated by Spain, to approve his divorce from his Spanish wife who had failed to bear him a male heir. At a time when other future nation states in Western Europe were educating their religious elites in Latin, the Anglican Church was creating a high form of English to be used for religious purposes, as exemplified by the English Book of Common Prayer and later the King James Bible. The scholars who created these new sacred texts were generally educated in French, plus they self consciously used Greek and Latin as models, and as the source of many new words. Neither of these religious works was written in the English of the day … but they became models for teaching and literacy.
Hebrew was already not a spoken language at the time when Judaea was dominated and conquered by Rome. Its grammar and orthography were standardized over many centuries by those who studied and commented on sacred texts, and often added to them with new commentaries. When rapid immigration made it possible for a linguistically diverse group to come together in the region around modern Tel Aviv, they drew upon this long tradition, but modern Hebrew scholars deliberately and self consciously created and added thousands of new words. Modern Hebrew is a standardized language, created barely a century ago, in a country with universal literacy and mass communications. Even so, some religious Jews still use an older version of Hebrew, the Ashkenazi religious dialect, in prayer.
“Why Did English Stop Changing? Let's Blame the Book of Common Prayer,” by James Fallows in The Atlantic, (August 2012).