The article itself is a bit light on actual specifics, but perhaps the ancient literature is less inclined to write about some project out in the provinces that didn't quite come off as planned, versus some of the eye-watering stuff they actually accomplished. I've not read Suetonius for a good 20 years or more, but I vaguely remember some piece where he recounts about having the engineering saavy to flood the amphitheatre in Rome to host mock naval battles. Well mock battles in the sense that the poor guys actually fighting and dying are only doing "pretend" battles, but you know what I mean.