How Philip Roth's style has evolved

As noted in previous posts, we don't read Philip Roth's novels for plot, but his first novel, "Letting Go," while it's by no means tightly constructed, in fact it "sprawls" across several sets of characters, many years, several settings, and a few shifts of narrative point of view, is a good old-fashioned story in some respects - not a potboiler, but not literary fiction as we know it today; in fact, it makes me nostalgic for those years, not all that long ago, when literary fiction and popular fiction were not so far apart. I don't know LG was a best-seller or a BOMC selection, but it certainly might have been - much less imaginable today. Roth's style evolved - his great novels of the 90s and the 21st century have a very open structure, not really snapping to a conclusion - but as I near the end of Letting Go I can see that he's building toward some emotional climaxes: a few highly dramatic scenes and developments (spoilers here, obviously): the death of the young boy, Markie, pushed out of bed by his sister - nicely told from the sister's point of view, though children have never been Roth's forte; the Herzes' adoption of a baby girl, with the threat of legal complications (we'll see how this works out). Ultimately, the great theme of this novel, as of so many of Roth's work, is the relationship between parent and child, particularly father and grown son, and we see these relationships from a number of different angles throughout this book - though as the book evolves, the main character's dad, Dr. Wallach, becomes less of a plot element (and less involved in son's life, as he prepares to remarry). Also, I note that literature - which was a main theme in the first section of the novel, as characters discuss at some length Portrait of a Lady, almost evaporates from the plot: there's no real sense, by the half-way point, that the main characters are literature profs; they could as well be ad execs of accountants or anything.