Vernacular Literature is important because it is translated into vernacular which was the "common language" basically it made it so that everyday people could understand the text.

the middle class.

During the 1100s, troubadour poetry was one of the most popular forms of vernacular literature in Southern France. Troubadours were poet-musicians who composed and performed lyric poetry about courtly love and chivalry. Their works were widely appreciated among the nobility and influenced the development of vernacular literature in Europe.

vernacular literature

You call literature written in the spoken language of the people vernacular literature. It often reflects the everyday language and expressions used by a particular group or community, making it more accessible and relatable to a wider audience.