Also, it feels like phones have entered that "Core 2 Duo" PC stage where upgrades don't really matter as much any more. I know software support can still be an issue, but at least on the iPhone side, I don't feel like I need to upgrade before my phone loses OS support.
visa and mastercards will not last another decade if hardware sales don't pick up soon.
I suspect you also have something of a generational thing with many younger students not even using PCs.
I have an iPhone 11 (fall 2019) and I see no reason to upgrade.
It does feel like we’ve hit a plateau. The only step up I can see would be on-device ML/“AI” models. Removing the latency and improving offline capabilities of something like Siri would open some doors.
And I may slide in a Mac Mini/Studio in place of my iMac at some point, I'm not really in a hurry in spite of being out of OS update support. It's basically a browser machine given I have a newish laptop.
If the 2012 lasted me 5 years back then, this M1 Pro should last at least as long since the things that drove me to upgrade from the 2012 (mainly thermals) are not a problem with this machine.
[1] Actually systemd-oomd to be precise, but let's not start the userspace OOM killer debate again in here
These figures exclude ARM CPUs, another possibility is that lots of people are switching/buying ARM devices.