Spinning HDDs (Toshiba bearings), keyboards and hinges on the other hand have all failed on me multiple times, in macs. but the fans kept going. The keyboards were the last thing to fail in the 2009 design, they last about 10 years.
Also while were at it, mechanical failure isn't always the biggest concern these days, Apple has had nVidia GPU issues (soldier and fab issues) in the past where they ended up underclocking them in a firmware patch in order to push failures out of warrantee.