>In my experience it's always just "easier" for people to pester those who should know the answers.

Your intuition is probably correct. It's interesting why private corporate wikis and other "knowledge management"/"corporate intelligence" systems fail to live up to the vendors' promises while public crowdsourced volunteer efforts like wikipedia.org and stackoverflow succeed. They have different social dynamics that software tools don't really solve:

1) Venn diagram intersection of typers & searchers is too small a quantity. The # of employees who will type out quality answers (typers) and # of employees who will search databases for answers (and attempting different keywords/synonyms when they initially get "0 results found") is too small to make internal knowledge databases flourish. Yes, the % of contributors[1] to wikipedia and stackoverflow is also less than 1% compared to lurkers but since that 1% in absolute numbers is much higher (e.g. 100,000+), that's enough to keep up the quality content on those websites.

2) out-of-band questions/answers that happen outside of the Q&A database. E.g. Bob catches Alice in the hallway as she heads out to lunch and asks her why WidgetX has foobarY and she can answers it on the spot. Neither are going to disrupt their motions so both can go sit down at a keyboard and type out the same Q&A again. Same situation with questions popping up on Slack or conference calls. Compare that in-office dynamic with remote Stackoverflow contributers[2]. You don't have those experts walking around your hallways so you must use stackoverflow to type out the questions. There are no out-of-band communication channels. This constraint adds to the quantity of content.

3) secretarial/administrative/housekeeping curation. Much of the usefulness of wikipedia & stackoverflow is the ability to ask questions in different ways with different wording but still end up at the optimal canonical answer. This happens because the community continually ads relevant "tags" to questions, flags duplicates (that had different wording) & point them to previous answers, and adds comments to old answers to signify they are obsolete. This makes the cross-referencing index of those public websites very good. In contrasts, corporate wikis usually have no full-time admin to continuously enhance the cross-references. Therefore, if a new employee doesn't know the exact magic words to ask a question, they'll get "0 results found".

If the underlying problem is people dynamics and incentives, it's very hard for software tools of any kind to solve that.

At one of the Big 4 firms, managers tried to incentivize contributions to the "knowledge database" by tying it to annual performance reviews. Guess what happened? At the end of the year, the database gets flooded with crap articles (e.g. Powerpoints and proposals for specific customers) uploaded to the db to get that requirement checked off. That type of useless content would be quickly deleted by admins on wikipedia and stackoverflow.

The combination of all the factors above results in corporate wikis being either 1) a barren wasteland or 2) a dumping ground for useless content.

[1] https://en.wikipedia.org/wiki/1%25_rule_(Internet_culture)

[2] https://stackoverflow.com/users?tab=Reputation&filter=all