I inherited 2 Quicksilver Powermac G4’s a few years ago, one was still fully functional too! As a stand-alone machine running software of its era, no issues whatsoever, but connect it to the internet and it just falls over!
Originally intended to use them to house modern internals and make decent spec Hackintoshes out of them, but when I realised just how much effort involved (not the Hackintosh part, that was easy, just bought a normal case in the end, but the cutting and modifying of the case to accept a “normal” ATX style motherboard and components I CBA with) they ended up doing a sterling job of speaker stand raisers.
Maybe all I need is a sheet of laminated glass and I’ve got a highly desirable Art Deco coffee table? 🙄