" Also the treadmill of computer progress means that keeping devices for multiple years has significant costs in performance compared to replacing it regularly."

The interval of replacement due to performance is getting longer through. A 10-year old high-end laptop is still pretty good for average user today, especially with an SSD. Most people need just something that can run web-apps and stream HD videos via browser. Buying a new laptop solely for performance is getting harder and harder to justify. I guess that's why Macbooks are attractive, they offer more than just performance.