Comment by OkayPhysicist

To add on to the HA comment: A lot of people have distorted ideas of how much availability they actually need. A lot, if not most, applications could probably get away with the absolutely abysmal 99% uptime, depending on how that downtime was distributed. 99% uptime could mean anything from ~3 days of downtime a year, 7 hours a month, 14 minutes a day, to half a second of unavailability a minute.

Like sure, it's not ideal, but real businesses almost never are. And, as you pointed out, most datacenters get dramatically better uptime than that.