There is programming that is like that - it is not all programming, and I strongly suspect not the the majority by dollars invested into developers - even it is less of an interior designer choosing paints and more of an entire designer designing an entire interior.

Once you get away from the very trivial side of programming, yes you are standing on the shoulders of giants, but the design decisions are in fact truly novel un-forced choices. Ask two people to make a "note taking app for university students" and you'll get two very differently shaped apps.