Melville Scott's commentary treats the Eucharistic lectionary as the centerpiece of the BCP's curriculum for Christlikeness. Bishop Taylor likewise recommends the reading of them as the most profitable parts of the whole Bible. Dearmer too called them the "most precious" readings "of all." And yet, for a not-insignificant part of Anglican history, three out of four Sundays, what would one hear in church instead? The lessons of the Daily Office. England had a slightly better record for longer, requiring the "Sunday Morning Marathon" of Mattins, Litany, and Antecommunion every Sunday and holy day, but eventually even that gave way to Choral Mattins with Sermon, as had been the standard in America. Popular devotions, such as we know of them, were based on the Daily Office, or else very simple indeed, like Bishop Gibson's family prayers, or Bishop Taylor's triptych of Lord's Prayer, Creed, and Decalogue. How did people in the days of Sunday Mattins "normally" experience the Epistles and Gospels, either in church or in private?
I think the simplest answer is, they didn't. Many folks are bemoaning the current lack of piety in America but the church participation was equally abysmal between the first and second Great Awakenings. And those revival based awakenings tend to fade out quickly leaving little sustained growth in the churches. The American attitude tends to be: I got saved, what need have I of the church? I read a Lutheran text recently which had an entire chapter devoted to assessing this phenomenon, and it was 100 years old! The Way of Salvation in the Lutheran Church by George Gerberding: https://archive.org/details/wayofsalvationin1919gerb (Chapter XXIII is the pertinent section but several others touch on the subject.)
I do not know how far back you're going or on what you base this. My mother informs when when she was young that Choral Mattins was indeed the main service on Sunday mornings. However, there was a Holy Communion service earlier in the morning.