I once managed a thoroughly non-critical server that lived in a closet. In the couple years I managed it, we had quite a few failures due to the UPS tripping and no unscheduled downtime at all from any other reason.

I’ve had massive problems with fancy (HPE, IIRC, but it wasn’t called HPE then) raid arrays caused by the controller being a POS. Using plain mdraid would have been far more reliable.

Sometimes I wonder if all the effort people put into protocols that run Paxos and Raft could be better spent running a small number of coordinator servers with manual failover. I’m suspicious that, in many use cases, leader elections cause failures more often than the leaders themselves fail.