Only to somehow confirm anecdotally what you said but in another area of constructions.
I have been working in and around the construction industry for the last 35+ years in Italy and in the '90's the firm I was working for had a department for pre-fabricated (concrete) buildings (more like condos or office buildings than "single" homes), which was led by an engineer that was - really - a technical genius and - besides him - we did have exceptionally good staff, both the technicians and the workers.
In the arc of more than ten years we tried everything and the contrary of it and after several , generally successful or mostly successful, built projects (with only a few minor issues in a few of them) we came to these conclusions:
1)you can make cheaper pre-fabricated buildings only if the level of finiture and overall result is cheaper or feels cheaper or looks cheaper
2) you can make pre-fabricated buildings that are as beautiful, functional and what not as "built-on-site" but that will cost the same (or more) as the corresponding built-on-site ones
3) the one and only difference was time, with pre-fab buildings we could build in 6-8 months time buildings that would have otherwise taken 18 months or more (this worked very well for rebuilding after an earthquake)
In the years since I was involved in several more similar to the US timber based projects for single homes or anyway one/two storeys structures, and "components" (like pre-fabricated bathrooms "cells" for industrial buildings and hotels) and my experience did not change the overall opinion much.
For anything that is "modular" or very, very "standard" (i.e. homes from catalog) there may be some space for fair competition (slightly lower cost for same or similar "quality" of end results), but when you start to include in it:
1) the local building codes (and possible needed deviations from the "standard")
2) the customers' changes/preferences
3) the architects/designers (with all due respect for the category) "whims"
It invariably ends up costing the same or more (money) and almost the same (time).
I have been working in and around the construction industry for the last 35+ years in Italy and in the '90's the firm I was working for had a department for pre-fabricated (concrete) buildings (more like condos or office buildings than "single" homes), which was led by an engineer that was - really - a technical genius and - besides him - we did have exceptionally good staff, both the technicians and the workers.
In the arc of more than ten years we tried everything and the contrary of it and after several , generally successful or mostly successful, built projects (with only a few minor issues in a few of them) we came to these conclusions:
1)you can make cheaper pre-fabricated buildings only if the level of finiture and overall result is cheaper or feels cheaper or looks cheaper
2) you can make pre-fabricated buildings that are as beautiful, functional and what not as "built-on-site" but that will cost the same (or more) as the corresponding built-on-site ones
3) the one and only difference was time, with pre-fab buildings we could build in 6-8 months time buildings that would have otherwise taken 18 months or more (this worked very well for rebuilding after an earthquake)
In the years since I was involved in several more similar to the US timber based projects for single homes or anyway one/two storeys structures, and "components" (like pre-fabricated bathrooms "cells" for industrial buildings and hotels) and my experience did not change the overall opinion much.
For anything that is "modular" or very, very "standard" (i.e. homes from catalog) there may be some space for fair competition (slightly lower cost for same or similar "quality" of end results), but when you start to include in it:
1) the local building codes (and possible needed deviations from the "standard")
2) the customers' changes/preferences
3) the architects/designers (with all due respect for the category) "whims"
It invariably ends up costing the same or more (money) and almost the same (time).