When I was growing up, there was an older than God Swiss Watchmaker at the end of our block. . . he looked just like you would expect a Swiss Watchmaker would look like, fringe of white hair, apple cheeks, and a little smile, but somehow he missed the lederhosen. He said that there were really only 19 bearing points on a standard watch that really needed a jewel. Everything else would be superfluous. If you added complications, then you might need a few more. . . but never as many as you might think.
Pretty spot-on.
Even so, to see the (useful) jewels set in gold chatons (secured with heat-blued screws, nonetheless) is a thing of beauty!