> instead optimising for hardware cost I imagine a big reason that they're on old hardware is cost - just because it's relatively cheap for someone in the West

> instead optimising for hardware cost I imagine a big reason that they're on old hardware is cost - just because it's relatively cheap for someone in the West to get a decent modern machine at a reasonable cost doesn't mean that it's the same everywhere, especially when there's big disparities in the purchasing power of the native currency vs. the sellers/manufactures currency. It's not so much an optimization, I imagine most users on legacy hardware don't choose to be, it's more likely that they can't afford more modern hardware or it isn't available for them to purchase. Another huge reason for users to stay with older operating systems (especially in business and government) is dependencies on legacy software - if an organization relies on software that has never been updated after Windows 95/XP and doesn't function on later versions then they're going to be stuck using legacy machine configurations until the process can be changed to something else. > stopped caring about resource usage and efficiency (energy usage and operator time) How do you know that they don't care about how efficiently they can use a machine for whatever they're doing? It's a baseless assumption. Even if your user percent that's stuck using older hardware/operating systems is in the single digits, that isn't an excuse to ignore their requirements IMO. Doing so is a sign of sloppy engineering, akin to designing a new mode of public transport, for example, that doesn't cater for disabled people.