So this is, believe it or not, true. Literature changed dramatically in the 20th Century because more than just rich people learned how to read. In 1870, England made it mandatory for children to attend elementary school, thus making every generation thereafter (mostly) literate. This resulted in the creation of "highbrow" and "lowbrow" art. The highbrow art is the fancy pants literature we're used to. The lowbrow art would be seen in material like the Penny Dreadfuls that arose at the turn of the century. It's something like the difference between an art house indie drama and a Michael Bay action flick, only in book form. In any event, English literature, after over a thousand years, finally became accessible to the masses.