Sacrosanctum Concilium wisely advises the avoidance of "repetitiones inutiles". This, of course, implies that some repetitions are not 'useless'.
But a prejudice against any and all repetitions is not a new thing among liturgists.
I have in mind today the old arrangements with regard to the Sundays in October. In the days of S John Henry Newman, in many dioceses including those of England, the first, second, third and fourth Sundays in this month commemorated, in turn, the Holy Rosary [and Lepanto!]; the Motherhood; the Purity; and the Patronage of our Lady. But, so a Dom Grospellier argued, certain modern festivals, wherein are celebrated this or that mystery of the life of our Saviour or the Blessed Virgin, are but useless repetitions of what is contained in the office of the season. "Thus, for example, the double Mystery of the Virginity and of the Maternity of Mary is expressed in a manner most beautifully poetical, and full of the symbolism dear to the Christian epoch when it was written, in the office of the octave [day] of Christmas, that is to say of the festival which we now call the Circumcision of our Lord. In the feasts for the Sundays in October, conceded to many dioceses, we find similar repetitions."
I spent quite a few decades teaching, both the younger and the older generations. And the most important piece of advice I could give to anybody setting out to teach members of either category is this: Don't assume that when you've said something once, you've done the job. You haven't ... however brilliantly you explained it! People learn at different speeds. And, above all, they remember different parts of what you say. If you aren't prepared to repeat yourself ... and to do so quite often ... you aren't much of a teacher. Don't expect your A-level results to sparkle!
The didactic element in the Church's Liturgy is subject to the same law. The widespread ignorance of the Church's teaching in our own time is, in my view, partly the result of a failure to grasp this principle.