Hard disagree on this wishful thinking. I've literally seen the submitted plans for my house - there was absolutely no architect or engineer stamp on them. The true mega-builders might do this, but smaller operations (say, 25 to a few hundred houses a year) don't.
In my subdivision (which will be a few hundred houses built by one company) the plans are all new to this subdivision, designed by the head guy, and there aren't enough houses of any plan to amortize "tens of thousands of hours" among them (they've built 4 copies of my house so far, for reference).
You don't need an engineer or architect involved in building a "normal" house or developing plans in large parts of the country. There's no calculations required, for the most part, either. The codes allow a prescriptive path to compliance, so if you fall the span charts in the codes, it's good to go.
The only real notable exception is in truss design - but that's never designed by an architect either. The builder sends the house design to a truss company along with required loads in the area, and the truss company sends back trusses that cover the space and hold the required loads.
Threads like this are peak HN - people who "know better" how the world should work (and hey, I wish I worked like that too) telling people who have actually experienced something their experience can't possibly be real. I actually have had a house built recently. I did a ton of research, and this builder was the best I could do in my area and at my price range (about $600k). The options get a LOT worse as you spend less on new constructions.
