For example, cars today are orders of magnitude more complicated than 50 years ago, but due to more efficient manufacturing technology, the auto industry has far higher productivity per employee than it did 50 years ago.
The weak link in creating ever more complex homes, with ever more stringent building codes, at faster rates, is to remove the "humans with nail guns and drills" from the construction process.
At some point, us meat sacks are the weak link in optimizing an industry. Humans can only go so fast. That's why (as you've said) we've seen massive gains in productivity for other manufacturing industries.
Are they doing anything different than what was available in a Sears catalog 50 years ago?
For American-style suburban homes, it's most efficient to build most of the home on site, and only manufacture off-site a handful items like roof trusses. People might not realize this, but a small crew can frame several houses in a single (very, very long) day.
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.
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).