This means the app devs refused to make their app work with modern phones for YEARS. no real excuse there.

It’s a Google thing, not necessarily an app thing. Apps will have a minimum SDK level (basically the oldest Android version the app can run on) and a target SDK level (the Android version that the app is optimised for, which is usually the latest Android version). Google keeps increasing the SDK level requirements for apps to be published on the Play Store, so if an app is too old and hasn’t received any updates, you will see that message. But chances are that the app will run just fine if you install it from an APK file.

It may seem ridiculous but it’s good because it prevents people from installing super old apps, which may leave room for exploits in modern versions of Android.

That’s the first time i see that

this is mostly a security thing, because old apps lack granular permission system that modern apps have.
(you can still pick perms on first start but it’s kinda messy and breaks apps

I have seen it too many times. I tried to install many apps from the google play store and it shown me that it was unavailable. When i installed it from an APK file, it was on the play store, and it would work fine.

Just ran into this as well with a different app.

I wonder if the organizations the old apps are associated with even know.

I imagine whoever did the app dev and publishing knows, but I bet a lot of them are contracted developers (and who knows if they’re even still around)