It's good planning ahead for when Apple no longer supports perfectly fine old-ish machines. Both my mother and wife are now using Linux not because their computers broke but because Apple gave up on them.
Oh my, the mobile market really skewed our perception of reasonable support cycle. What a crazy world where 7 years is a “pretty long support cycle” for personal computers.
I have money to spend on computers but I still use a 10 years old laptop running windows and Linux (both supported) and with absolutely no desire to upgrade it as it runs better than when I bought it (after a ssd swap and more memory). There’s nothing that I do on my personal computer that would be improved by purchasing a new machine. Same goes with most people I know.
Is it? Windows has always had an extended support life cycle if ten years, and Windows 11 is heavily criticised for their new restrictions on hardware. I've seen Windows 10 run just fine on budget devices that go further back than that.
You can get the most recent Ubuntu LTS to run on a ten year old Thinkpad without issue. The performance may be limited bytthe hardware, but the software isn't the problem here.
Honestly, if I were to pay the premium prices Apple asks for their products, I'd expect them to outsupport a bunch of hackers that had nothing to do with the hardware.
On top of that I don’t think anything older than a core 2 duo is fast enough to use for web browsing, and most of those macs can be patched up to big sur using the various community patchers.