5 years is no longer "old"
Devices become "old" when their performance degrades to the point where it impacts productivity. This used to be pretty much entirely down to the steep drop-off in performance of old-skool hard drives as they aged. These days, most 5-year-old business devices will have an SSD, so there is no real reason to replace them purely on the basis of age until parts start failing at an unsupportable rate.
As for performance, newer devices are definitely faster and more powerful... but is that delta change enough to justify the expense and staff resource of replacement? If a 4-year-old laptop is still performing adequately, why pay £££ for a 30% performance hike? And that's where AI comes in I guess... but Open AI and MS have screwed the pooch on that one by supporting the AI hardware demands at the server side, not the computer side. Why should customers pay for new hardware for AI when they already get AI on old hardware? And we have been told repeatedly for many years that this sort of thing is exactly the reason we should all use the cloud, so why is it our problem to fix?
A lot of people can see this for exactly what it is - a dishonest attempt to convince us that perfectly serviceable hardware is now obsolete. No wonder there's low uptake.