In my experience, more than six procedures is crap.
The standard does not say "document only the 6 procedures". Section 4.2.1d of ISO 9001 charges the organization with documenting what they deem necessary to plan, operate and control its processes effectively. Achieving consistent quality requires documenting how an organization's processes and activities should be carried out. The standard applies to all types and sizes of organizations. It would be impossible to list the required documents for all those types and sizes. For all but maybe one-man shows, the documentation required to achieve consistent quality is substantially more than "the 6 procedures".
Having detailed documentation of your processes is the only way to control them effectively when more than one person does the process, or when the person doing the process changes, or when you do them intermittently, or nearly in every other real circumstance.
Documentation is also truly effective way to improve your processes. Improvements are recorded in the documents, compelling any required changes from even operators very experienced in older ways of doing things, and as importantly, capturing those operators' knowledge so others can do it as well as them. I'd be very skeptical of the effectiveness of a continuous improvement system without documented procedures on which to reflect acquired knowledge.
So all in all, maybe all you do need to frame a certificate are indeed the 6 procedures and a myopic auditor.
But to put out quality, you need to document your processes.