In my experience:
1. Well meaning people try to build wikis/confluences/whatever that turn into backwaters of slowly rotting stuff
2. Beyond a certain extent that they can hold in their heads, most other people give up.
3. Some people hoard knowledge and use it for personal advantage.
I dont know what the solution is. Maybe an ai that reads every chat and email and commit - and builds some kind of browsable, queryable, executable knowledge trove.
This way, new and updated context is not lost on the next user.