I am not going to argue with the legitimate claims of inconvenience (or worse) thanks to deprecating old APIs.

But we have a natural experiment of the opposite: Microsoft has bent over backwards to maintain back compatibility. And those old APIs have been the major sources of vulnerabilities, fragility, and maintenance cost. They do occasionally bite the bullet (e.g. old versions of Word are no longer readable) but they go out of their way not to.

I really don't like Windows for my own technical reasons but I have tremendous respect for the amount of effort MS has put in over the years on this front and I sympathize with the consequences.

Apple has a much smaller "surface" (both vulnerability attack surface as well as surface ear of their own code base) which makes many technical decisions much easier.

So either way means a choice; you can't say one is absolutely superior to the other.

I'm not sure this is all that accurate a description of the current state or priorities of either Windows or Mac OS. Microsoft actually did exactly what the other poster is suggesting - use virtualization to provide support for a previous OS (XP mode in Win 7). And that was 10 years ago.

Except Apple already took the same approach with PowerPC applications.

IIRC, you could still run these apps on Snow Leopard in VirtualBox by using Rosetta. It's PITA but I would still say they should offer Snow Leopard image for the purpose of having Rosetta support.

I'm not saying Apple will do anything like this but it would be nice of them to do it.

Rosetta relied on a binary recompilation technology they licensed from Transitive. IBM bought it up and changed the licensing such that it was no longer economical for Apple to ship it, which is why it dropped really suddenly.

Free copies of Snow Leopard would likely cost them a lot in fees to IBM

Maybe a point in time image wouldn't be a bad thing, but what do you mean by "that'll be maintained forever"? That it'll be downloadable, or that Apple should be responsible for security updates, etc, on those legacy OSes?

Apple makes previous versions of macOS available to download, and you should be able to cover those into something your virtualization software can boot.