It's interesting to look at the impact of regulation and supply and demand on the construction industry. (As with most posts on these topics, this is mostly speculation which would need to be researched/measured to be confirmed but the conjectures are testable.)
As a simple example, one can observe that houses built more than a hundred years ago are still standing strong while those built as recently as the 90s are being torn down and replaced with higher quality construction. Of course this is a generalization and there are clearly exceptions at both ends, but what if we take a look at the factors in the marketplace?
Houses built a hundred years ago in the US were constructed in a time of zero regulation and yet many are still standing. Perhaps the quality of materials played a role here; you got more wood in your 2x4s back then (see 1920s construction for an example). Or maybe it was the manual effort involved; hand-cut blocks and studs, plaster walls and so on. Of course it's hard to count those that have already fallen down or been razed so there is a bit of survivorship bias at work here.
The sudden surge in demand for houses after World War II (think G. I. Bill) presumably led to a general decrease in construction quality as it was much easier to make money slapping together cheap houses. Government regulation presumably followed which brought some balance back into the market, likely right around the time that the supply and demand were beginning to balance themselves once again.
What about the individual contractor, carpenter or plasterer? Could the introduction of powertools have a more significant impact than any of these other factors? There's no doubt that such modernization has dramatically increased the efficiency of construction. However, given the differences between hours to evenly plaster a wall or ceiling compared to the minutes needed with some sheetrock and a portable screwdriver, what would we expect to see happy to fit and finish quality?