As it pertains to system documentation, how are your teams generating documentation? Historically, my experience is that we've used word documents for things like server build documentation. In cloud, system documentation can often be contained within the platform that it is used to build it in the cloud (for example in Azure in ARM, Bicep, or blueprints). That said, I still feel that there is value in having build documentation. Some teams us WIKIs. What documentation are you seeing used in your organization?

Documentations are never static and keep evolving with time if not it should be in most cases. Keeping documentation in a isolated folder is not helpful thus we should look for cloud such as SharePoint or Knowledge articles on ITSM tool like ServiceNow.

Reason for storing the information in the SharePoint is not only accessibility but also different versioning, edit logs. There are categories of documents like architecture, Enterprise architecture etc which can have its own space whether in specific EA enabled tool or SharePoint.

New AI tools are also integrating with cloud placeholders like SharePoint and its knowledge out of all the documents specific to process or IT issue resolution or workaround can be used. 

Example Microsoft teams AI bot can be integrated with CHATGPT and can be used for end users and for internal technical teams to search information from documents, RCA, Problem management. There are multiple use cases.

We use Onenote. It resembles the word documents, but all documentation is searchable and can be easely structured. It is also accessible from wherever your need it, on any device. Security follows the office365 security.