Do you believe it's important to have consistency across repositories?
For example, an organisation has hundreds if not thousands of repositories in their git solution. Is it important to you and your organisation to have an established baseline for what is considered "good quality" or "acceptable standards"?
Totally, actually the more projects and people involved on them the more important standardisation becomes.
Some of the advantages are: easier to find information across projects (similar structure), less time spent on creating documentation (you don't need to figure it out every time), easier to switch from a project to another or join a new team, less time spent on formation for new employees and collaborators, etc.
It's true that usually documentation is one of the least important topic on software development, specially as Indies were we try to just get it done and postpone non essential work for the future. But the bigger the project or company becomes more chaotic it gets.
Actually I've been improving my documentation (standardize, simplify, making it easy to understand, etc.) lasts months because I want to grow a team and I cannot effort too much time on teaching everyone how every project is done.
It took me days to do so and I think there is business potential on this area even if there are tons of OpenSource tools already.
Yes.
During last year's Google Code-In, I worked on some MetaBrainz repositories.
For me as a new contributor, I found it very confusing to find in some repositories a CONTRIBUTING.md, and in some it was included in the README. Some had a dedicated docs website and some had a quick README.
Having this a uniformed standard (for example, do you have a docs website for everything or do you use the README as docs?) is very helpful to newcomers.