There's a reason we don't just "let the builders build". We used to do that (certainly to a massively greater extent than we do now), and the result was that although a few of them managed to construct monuments we can all be proud of, most of them built a pile of crap and/or damaged the places they built in and the people they nominally built for. This is true of literal buildings, but it's also true of a great many…
In that sense, the history of smartphones looks a bit more impressive than that of running water...