I worked on a house that was prefabbed in Indiana and trucked over here where we have tight building regulations. Like all electrical MUST be run through EMT conduit.
So imagine my surprise when I found a rats nest if Romex in the mechanical closet. None of the wires were even trimmed, it was a tied up ball of wires going into the panel.
I'd have the same concern getting a cheap house shipped in from overseas. What corners were cut to save money? Who can you call when you discover an issue with the construction 6 months later?
I see the appeal, I just don't think I'd be comfortable living in it