There is no loss of literal meaning when we say “Holy, holy, holy” in place of “Sanctus, sanctus, sanctus” , but the connotations of history, millennial traditions, and an ethos that constitutes a sacred semantic are all gone, as they must be from any vernacular translation. It takes ages for a language to accrue those symbolic attributes. The very modernity and normalcy of vernacular speech automatically excludes them.
More and more parishes are serving multiple linguistic communities, and the common practice of having a designated “Spanish Mass” or “Vietnamese Mass” doesn’t solve the problem here, because there will always be worshippers whose native language is not the vernacular of the moment. In effect, they are placed at the lowest table of the banquet. Latin has the peculiar properties of a dead language: besides owning a vocabulary of unchanging meaning, no one learns it as native speech anymore. When liturgical Latin is spoken, there are no natural superiors.
Read full essay by Joseph P. Swain on Adoremus website.