Given that it's been five years since Apple Silicon debuted, I think the cliff for the Intel Macs is fair. I think this year's cliff was pretty steep as it looks like a number of Macs that had the T2 chip got the axe this year. I'm betting the CPU and GPU power to draw all those transparent glass material interface elements would have caused performance dips that Apple would never allow (as I feel they learned a LOT about the performance of Aqua in the early days of OS X on less capable hardware and how negatively viewed it was through the first 2-3 iterations of the operating system). At least most of those old Intel Macs should run some flavor of *nix pretty well without a ton of effort. They've come a very long way to fully supporting the hardware Apple was putting in their Intel products over the years.
Yes, I know that it's been six years, but I spent like $2000 on my Intel Mac Mini (which, in retrospect was a gigantic mistake - but that's a story for another time) and it would be nice to know that it's going to last forever. So that I can OBVIOUSLY get my money's worth.
But, from a less biased perspective, I think we've reached a point where, at least for many desktops and many laptops, you're not seeing that much of a need to upgrade after 6 years. The aforementioned Mac Mini was relegated to the role of an average office computer and it manages web stuff, writing, managing documents, and other things perfectly fine.
