Many years ago: HDDs died like I've never seen it before, one every few months with just a couple of servers.
ca. late 2013: We had some production systems running on Hetzner hardware, we regularly! called their support to tell them the DC lost connection because our monitoring apparently was better than theirs and they acted surprised for not hearing something yet.
Only like 2-3 years ago: Got a new server, had SMART issues and had to have the disk replaced before the first 24h after ordering were up.
An ex-coworker of mine joked they must have added the "please change the disk" option in the support form just for him because he was running 20+ servers and actually had to call them every week to replace a dying disk.
Yes, this was all years ago - but I'd rather pay servers out of my own pocket than be oncall for production servers there, ever again.