Code can be 5% of a business, while the entire software part is a much higher proportion. The software concern of a business encompasses way more than just coding: testing, environment building and maintenance, source control, backups, security, and much more. Realizing that the actual executable code is such a small part of delivering a software product is a really important step in maturing from a code-monkey programmer to a capable software engineer.

Your watchmaker analogy is actually a pretty close parallel to software. The mechanical functioning guts (executable code) of the watch, the gears and ratchets and springs and all, probably are about 5% of the business. But the entire watchmaking concern, from supply of materials to fashioning the face and wristband to final assembly and inspection, encompasses much more.