Back in 2003-2007, I worked for a home builder who vertically integrated and went for maximized modularity. In '05 we expanded our truss yard to 2 large presses and 4 automated saws, and added a wall-framing yard what worked the same way as the truss yard. Add in that they bought a concrete company to do the slabs, and a 2-story house could go from pour to sheeting in 35 days. Plumbing, electrical, and finishing jobs could take as little as an additional 30.
Since the parent company dissolved them in '08, I haven't seen any of the other subsidiaries using the same techniques or scheduling, and it's always rather surprised me. They invested literally 10s of millions of dollars into us figuring out how to make it all work, then trashed the knowledge.
I think the lack of vertical integration could be a part of it. For example the framers don't have much incentive to make things easier for the plumbers or electricians.
There was a recent HN post on a shortage of electricians that got me to thinking why studs, which already come pre-cut to exactly 92 5/8", don't also come pre-drilled for wiring at outlet and switch height (at least I've never seen that in wood studs).
The builder of the new neighborhood going up near me uses these techniques for all rooflines. They still frame on site for flooring and walls, but they crane on pre built trusses for the roofs, built nearby.
Since the parent company dissolved them in '08, I haven't seen any of the other subsidiaries using the same techniques or scheduling, and it's always rather surprised me. They invested literally 10s of millions of dollars into us figuring out how to make it all work, then trashed the knowledge.