Italian dialects, especially Sardinian and Barinese, are different from the base/Etruscan Italian that they can be considered different languages. I understand that they are not considered as a result of Italian nation-building. 'Abbiamo fatto l’Italia, ora dobbiamo fare gli Italiani'.
But were they always considered the same language? Would an Etruscan from 15th century consider Sardianian or Barinese or Sicilian etc. to be the dialects of his own language?
u/AlviseFalier answered a somewhat different question recently, although it also gets into the issue of what is an Italian dialect or a separate language:
It depends on the language and the period. Some of them had enough prestige to be considered languages, like Genovese, Venetian, Neapolian or Sicilian, while others were always considered low prestige popular dialects, like Romanesco.
Also, there weren't Etruscans anymore in the 15th centuries, but just Tuscans. Etruscans were assimilated by the Romans a thousand years before.