Comment by noirscape

Oops, yes, I meant a constant non-zero rate. It's slightly above mobile phones, where the developer is treated as the problem that needs to fix itself.

Stuff written for one version of MacOS will probably work for the next few versions, but there's just as likely a chance that Apple has decided that you need to do a full on update of all your older tools. Things like dropping Rosetta, 32-bit from the kernel and so on and so forth. There's not really any recourse, unlike Windows and Linux where you can usually finagle a workable solution without having to resort to updating everything all the time (so platform churn exists, but a user can theoretically choose to avoid it).

This is unlike phones, where there's basically no real expectations for when you need to update stuff, so it becomes a case of "you need to test every version". The lack of respect for tool stability is just one other reason why the mobile ecosystem is the user-hostile hell it is; this platform churn pretty much is one of the two roots of why mobile apps are Like That. (The other being that running your own choice of tools is treated as a privilege, not a right.)