> you have documented and defined your methods (i.e. business logic) well

Wishful thinking, though, in many cases. When software dictates the workflow, the code _is_ the business process documentation. Add a new function to the code? Did you go and update the docs, too? Takes serious diligence, takes bigger teams, hard for a small business systems department to keep up with that. That's why they use low-code platforms, aside from the skill gap (i.e. once you can really code, you tend to not want to write business systems stuff anymore)