The other way to look at it is as technology improves so does energy efficiency. What is the cost saving of taking older more power-hungry hardware off the grid

The other way to look at it is as technology improves so does energy efficiency. What is the cost saving of taking older more power-hungry hardware off the grid? Planned obsolescence encourages timely upgrading so end users can take advantage of recent innovations. Similar to how a rolling release delivers bug fixes more expediently than a code-rush major releases interspersed with occasional patches. (I'm not saying definitively that one is better than the other, only offering both perspectives.)