Because planned obsolescence is *********?
I really enjoy the things tech can do and I’m fascinated by shifts like Apple moving to ARM based Macs. But not everybody cares about that. While Apple’s roughly seven year window of support (generally five or six major macOS versions and then a couple years of security updates) is more than some manufacturers offer, the fact remains that the machines appear very solidly built, which is why you see so many old Macs out there doing the day to day grind.
Despite Apple’s attempts to shift users into a new machine, two things have come about that throw a wrench in their plan. One is that the horsepower war of the 1990s and 2000s computer era just doesn’t matter much anymore. If you can take a 10 year old Mac online and do everything you need to, with decent performance, there’s no need for a new one. Contrast that with the 1990s when PC power was doubling every couple years and so software was getting more complex to match, and a 5 year old computer was a doorstop. Not so much anymore.
The second thing is there are dedicated communities who want to see these old Macs continue working, whether because of money, because of time, or because of the environment. Projects like OCLP exist that extend the lives of your typical Mac far beyond what Apple officially supports. One of my Macs, a 2014 iMac, runs Sonoma this way and runs an Emby media server. Despite its age and specs it’s more than enough for that simple ask, even when transcoding is required.
So, in short, there’s a lot of reasons. I love new tech but I’m far from rich, so while a new phone every couple years is my treat to myself, I expect my Mac, iPad, and other machines to last a good deal longer. Ain’t nothing wrong with that.