I don’t think you’re implying this is exclusively an American issue or anything but that’s just the nature of construction unless you’re paying top dollar for accuracy when it matters.

I’ve been on a hundred or more construction sites and I’d confidently wager that most houses don’t match the plans perfectly because of unforseen reasons…equipment changing due to lead times, electricians running their conduit in the wrong stud bays, etc. I’ve had to do a lot of creative problem solving and design modifications are inevitable. That’s the only thing I really miss from my old career