This. 90% gives surprisingly large error budgets; that’s about 72 hours of downtime a month or 36.5 days a year.
I would guess most home labs are at or near 99% availability on hardware.
Scale is part of it too. I could pack my homelab into the car and take it to a friends house. They have the space, power service, and internet to accommodate me. A full data center doesn’t have that option, at least not for free-ish.
When you can buy 4 USFFs for the price of 1 new one, and run 2 have have a test one, and one for spares I'm not really sure what everyone is concerned about.
Enterprise, engineering, industrial grade equipment is the same high quality level, be it a server or a desktop meant for extreme environments.
Too many people are only purchasers of consumer grade equipment and would be surprised at what a huge difference the corporate/engineering/industry spec stuff is like.
I would guess most home labs are at or near 99% availability on hardware.
Scale is part of it too. I could pack my homelab into the car and take it to a friends house. They have the space, power service, and internet to accommodate me. A full data center doesn’t have that option, at least not for free-ish.