In addition, value added per hour can be a sign of productivity loss, but is also impacted by shrinking margins (which they note is the case - but shrinking margins has nothing to do with productivity and everything to do with competition).
Also the article says "Many building professionals use hand-drawn plans riddled with errors" - Hand-drawn plans? This isn't my experience in the UK (I design warehouses and have worked with lots of primary contractors). CAD here is pervasive, and anyone with a hand drawn plan would be laughed out of the room (unless you were literally a builder doing a quick sketch - in which case CAD isn't a replacement).
And the article then recommends... self driving bulldozers as one part of the solution? This is so far away from being safe on a worksite that it's nowhere near an immediate concern.