That's not a fair comparison at all. A bathroom or kitchen is something they have worked on a hundred or more times before, with little variation. In contrast, software is almost always original. If you ask me to implement the same software a hundred times with minor variations, of course I can give you good estimates without stress.
THIS exactly is what Software “professionals” have amazingly successfully been able to convince everyone. That somehow what we do is “special” and we just cannot possible tell you how long XYZ is going to take… Software “is almost always original” is the same argument as if an incompetent carpetner would say “sorry, no two kitchens are alike and while I use same sh*t to build them I have never built yours exactly and hence I’ll send you the bill when I am done.”