Why don't Catholics use the Bible at Mass?

Answer 1

The Catholic Church is replete with traditions. As such, the Lector1 reads scripture from The Bible. Albeit, the majority of attendants do not bring a Bible to mass as they entrust the scripture reading to the Lector. The Church provides Lectionaries so that one can easily review all the readings used in a mass.

Footnote:

1. Lector - one whose chief duty is to read the scriptures in a church service

Further explanation: the Reader (who may be a lector, lector is one of the minor orders on the way to the priesthood) reads only the first two readings, the Priest, Deacon, or Bishop reads the Gospel. The readings are set up on a three year cycle to cover the entire New Testament and a good portion of the Old Testament. All of the readings are contained in Missals, Missalettes, or Hymnals for the people to read, thus if they want to read along with the reader, they do not need to bring their Bible from home. Plus the readings are invariable - they are the same for each particular Sunday or Feast day, and NOT dependent on the whim of the celebrant (priest) who is a servant of the liturgy, not it's master.