“What may I ask, would be the purpose in that case, of saying it in Latin at all?”
Latin is the native language of the Church. I learned Latin as a child going to Mass, only to learn the grammar and add to vocabulary in high school.
Translation can lose a lot and that goes for the prayers also. What in English sounds off, in Latin, the original writing is beautiful and conveys the orginal intent of worship and piety.
The old testament was written in Hebrew, the new testament was written in Greek. Why bother with a Latin translation.