First of all, it is my experience that wikis often seem to grow and thrive quickly, but behind the scenes there is no reasonable way to keep them up to date - except through the discipline of the authors.
This discipline often quickly wanes once you have gotten rid of your knowledge and incorporated it into the wiki. It seems to be in good hands there.
But after a short time, in particular technical topics will become outdated, and so the distance between the wiki and reality grows steadily. And there is no guarantee that the authors will take care of their outdated content. That is precisely the moment when no wiki is better than an incorrect wiki.
What works on Wikipedia often does not work on small wikis, because small wikis do not have the number of tens of thousands of authors who, through mutual exchange, almost automatically keep the content up to date, because there are usually far more than just one user behind a particular piece of content.
Unless there are wikis that have an expiration period for each article, after which the author has to reconfirm the content every time the period has expired.
Otherwise, the article should automatically be flagged as "possibly outdated".
Just my 2 cents.