Imagine if the tools in your shed turned to dust after 5 years. And these are analogue, physical objects. Digital objects if stored in a properly error-correcting medium, can last indefinitely. No excuse for this.

Imagine a library of books where every book over 5 years old is burned.

You deserve more upvotes, because your analogies are not far from the truth. We are living through a black hole of history, where valuable information is being destroyed at unbelievable rates by virtue of it becoming completely inaccessible through the planned obsolescence of incessant upgrades.

That's not a reasonable comparison. A more accurate one would be something like having a 25 year old 12V battery drill and expecting the manufacturer to still make and sell the NiCad battery pack it used. Sure they could do it but it doesn't make any sense. Technology has moved on and there's no consumer demand for it.

I agree that Apple and other companies are too aggressive about breaking compatibility but it's not the same thing as tried and true physical objects.

This is not a good comparison. Nobody is trying to use a new battery. They just want old battery to continue working as it has. Code does not rot like batteries wear out. Companies deliberately break compatibility, and then they blame arising problems on “code rot”.

Changing icon should not require a new build. A new build should not require iPhone X support. iPhone X build target should not require Xcode 9. Xcode 9 should not require macOS 10.12. OS update should not break old Unity3D. Upgrading Unity should not break builds.

These are all examples of shitty engineering decisions that throw backwards compatibility under the bus for shaky (expedience, mostly) reasons.

I mean they often still do …

https://www.homedepot.com/p/Milwaukee-18-Volt-NiCd-Battery-P...

We basically have that with the way publishers license ebooks to libraries. :(

Libraries do cull their collection and sell books that haven't been checked out in N years, though, which is sort of similar.

Here's the thing though—if I want one of those books that the library removed from their collection, I can do some research and track down a copy from another source.

On iOS, there is no other source. Once Apple removes an app from their store, that's it—unless you bought it already, it's gone forever, no recourse.

Couldn’t you do the same and find the author and get the .ipa file?

No, you can't sideload on iOS. IPA files are tied to your Apple ID.

I still use EasyToon, originally published 1998. Then again, I'm on the only operating system that actually values backwards compatibility.