I think it means they'll last for decades when actively used and left in a sane environment. Most of the original Model F's were sent to the landfill long ago,

I think it means they'll last for decades when actively used and left in a sane environment. Most of the original Model F's were sent to the landfill long ago, so the current supply is from electronic recyclers, fished out of the trash when somebody's office dumps old stuff, or found in somebody's grandma's barn.