TBH, in my last 3 years with Hetzner, i never saw a downtime to my servers other than myself doing some routin maitenance for os updates. Location Falkenstein.
You really need your backup procedures and failover procedures though, a friend bought a used server and the disk died fairly quickly leaving him sour.
Younger guy with ambitions but little experience, I think my point was that used servers with Hetzner are still used so if someone has been running disk heavy jobs you might want to request new disks or multiple ones and not just pick the cheapest options at the auction.
(Interesting that an anectode like above got downvoted)