It’s also worth noting here that the reading of Sacred Scripture during Mass is not strictly for the sake of the congregation: it’s not merely teaching the people what the Bible says. The readings are very much so a ritual, with symbols that contain an important meaning – this is most easily seen in the TLM, where the readings are done from different areas of the Sanctuary:
The Epistle is read towards “Liturgical South.” The priest (subdeacon in Solemn Mass) stands on the right side of the altar, and reads the Epistle to the “south” because the Epistles were written by the Apostles to those who had already been converted, who were generally in the “south” (i.e. Jerusalem and throughout Palestine).
The Gospel is read towards “Liturgical North.” The priest (deacon in Solemn Mass) stands on the left side of the altar (at the ambo in Solemn Mass), turned facing partly away from the center of the altar, and proclaims the Gospel of Christ to those who have not yet been converted (i.e. the Gentiles in Greece, Italy, etc., to the north of Jerusalem).
So specifically with regard to the Holy Mass, proclaiming Sacred Scripture is not “Bible study” time, it is a liturgical ritual (as evidenced by the symbolism of reading the Epistle to the converted; the Gospel to the unconverted), so it does not need to be in a language the congregation understands; it makes more sense for it to match the language of the rest of the liturgy.
In my opinion, the common practice of repeating the day’s readings in the vernacular prior to the homily is the ideal compromise between ancient ritual and modern practicality.