That's an extremely interesting thought. Perhaps we will see organisations in the future structure themselves more like a suite of unit tests. Instead of getting a developer or software house to plug a specific need in their org and being entirely outside of the development process: they will reflect the development process organisationally to ensure they catch any problems with the current output and just feed the box new prompts to increase their efficiency or efficacy.
Their competitive advantage in their field then becomes the range of their tests (borne through experience), efficiency in running their pipeline of testing and ability to generate effective prompts.