Earlier quoted context omitted.
Not speaking for the GP. I use MkDocs and keep my personal notes. The only weak spot for me is that I haven't fully grokked search and as my notes grow, it can be harder to find things. I alternate between figuring out how search and how to bolt on some other search utility. MkDocs includes a utility to publish to Github pages but I keep my notes on a self hosted Gitea server and serve using "python -m http".
Is this a fully collaborative tooling with self linking? Having hundreds of out of date, and insecure word documents is a dismal affair when you get a call in the middle of the night. For issue resolution, documents steps are moving right in to the ticketing system for linkage to incidents. That’s fine. For general documentation though. It doesn’t belong in the ticketing system and what a pain in my ass.
I edit using VS Code and it provides help with linking from one document to another, including navigating to the file and even linking second level ('##') headings. MkDocs can report broken links when it builds the site.
Collaboration could be through sharing a Git repo. Perhaps other other ways I can't think of at this moment. Any way you could collaborate editing text files should work.