That passage really brings into perspective how old Scientific American is, or maybe how little ago it must've been that the composition of the sun was discovered. This was during the American Civil War.
He's incorrect in that the Standard Model firmed up in the 1970s. But since then, fundamental physics has been nearly stagnant.
More broadly, the era of exponentially growing knowledge of the basic foundations of the universe cannot last long. Historically it will be seen as highly anomalous. Most of history will be one of scientific stagnation.
Any exponential growth process runs into fundamental limits soon enough. This is as true in physics as it is in any other field. Accelerators are close to their practical limits, for example.
