Meanwhile, Apple has gone through two deprecations of CPU architectures: first PowerPC and then Intel. Macs are nice, but I wish they had the same commitment to backwards compatibility.
I'm not sure it really matters, in the end. How often would people want to run PowerPC-era Mac software on modern hardware natively if they could? The HN audience will include a disproportionate number of people who do, so you guys aren't included ;-)
I haven't used a Mac in several years but it seems like the whole Apple mindset is more appliance like, that if you bought old software you just keep running it on the original old hardware, and given the problems with Microsoft's eternal backwards compatibility approach (applications and the OS bundling forever ancient code and keeping ancient interfaces around forever, and ending up with a disproportionate number of API calls numbered foo2, foo3, foo4ex), I'm not sure either way is strictly superior to the other. There are trade-offs with both.
I think some creative people, e.g. writers, might like to be able to continue to run their favorite old word processors if they could. Every so often you'll hear about a writer who's still using Wordstar or WordPerfect or some other old software because they know it inside out and it does what they need.
Of course, using old hardware has plenty of disadvantages (the increasing scarcity over time as parts become impossible to acquire) but even now you can find power macs for cheap. Your average ebay listing is pretty ridiculous but I snatched a G4 ibook there 2 years back for $14 USD, essentially in like new condition.
Korg released an audio DSP playground in a PCI card called the OasysPCI which never got OSX drivers, so I have a MDD PPC Mac to run that. There are probably better things running natively today, hey instruments are things that shouldn’t be obsoleted, since they all have their own sound. Most of the rest of the ancient software I run is run under Wine (which worked quite well up to Mojave, but became difficult when Apple killed 32 bit support) because Microsoft has done better at retaining backwards compatibility. So now I have a laptop permanently stuck on Mojave.
And it's not an academic one - a large percentage of somewhat older Mac-native Steam games don't even start.
It includes much more recent software too. It seems like half the mac games on Steam are 32-bit binaries published before October 2019 that no longer run on modern versions of macOS.