The link checker used to be run only a few times a year due to the effort of dealing with the results and server resources. The process has been improved and now it runs ~ every month (I think it's ~1 week to check all the links and then a recheck after ~2 weeks for anything flagged bad, and then it notifies editors of problems.)
Although it has been improved over time, the link checker isn't perfect. Also, it can't find changed content. It is still valuable to hand-check all the links in a category, especially ones that were built more than 3 years ago. This is one area that the public can always help us out with.
Although it has been improved over time, the link checker isn't perfect. Also, it can't find changed content. It is still valuable to hand-check all the links in a category, especially ones that were built more than 3 years ago. This is one area that the public can always help us out with.