Forgive me, it was HeimatBauer who wrote that. I got it mixed up. Sorry!!
Yes, and I still stand by that. Of course, you can’t look inside the wall of a used house you buy – but at least there is a chance that the builder did. When you buy a house like a steam iron, it is already certain that it was NOT done.
Before I built, I struggled for years with the thought "how do I actually do this" and whenever I passed a masonry construction site in my area, I noted the place and time. About 1.5 years after moving in, I went there, rang the bell, introduced myself as a neighbor and asked how the experiences with the house were now. The most striking experience was a property with two virtually identical single-family homes, same location, same basic house, only minimally different in fittings, but diametrically different assessments: The first builder shouted like a fishwife, nothing was as agreed, and so on. The second builder just laughed and said, "well, with me everything was as desired – I was also on the construction site every day and not only at the acceptance like the neighbor."
If you can’t or don’t want to do that yourself and also can’t or don’t want to afford a value-added webcam, then IMHO you are better off with a ready-made house.