Mandating an upgrade by obsoleting the OS is going to add to our environmental disaster, the newest IPCC report says probably +1.5 C more by 2040 at current trajectories. I wish influential environmentalists would start shaming Microsoft.
I agree that phones that are 4 years old are fine for most of the daily stuff, and even haswell PCs are still perfectly OK for the office, but this segment is a bit different and depending on the use case even earlier updates might be useful (like switching to pcie4/5 etc).
btw since I meant 4 years from now it also means that those unsupported workstations are not even new today, they could be running 2+years already, and 6 years upgrade cycle is not that bad
a) cheaper to replace
b) see updated answer - if these will be running for 6+ years at that point, it's mostly ok to upgrade them
Which isn't to say that modern apps and websites would run well on ten-year-old hardware—but there are equivalent apps and websites that would have run fine. In other words, the only thing you're getting with new hardware software bloat...