No house I ever lived in was ever made by experts. The apartment building I grew up in was all built by minimum wage guys that may or not even speak the language of the building overseer and had zero specific training or certifications. Some architect somewhere did the plans for a standard building, which the developer purchased and just used.

Then the only "experts" (not even close, just a guy with a form and some technical training) are the building inspectors who come at the end to verify if some stuff is done up to code.

Other than the original architect who draw the plans that got used for many buildings and the electrical engineer that cleared the electrical, no experts were involved. This is basically how the whole city and most of the country was built.

There's no expert mason or painter or whatever involved. Just a dude that can hold a paint roller. That's the same as going from a craftsman programmer to some dude with claude. Individual quality goes down, but more importantly price goes down way more and so many more people get access to much better quality than having nothing.