And then you have the other side, where the company doesn't upgrade the app (either cost savings or the company went under) and now you have an expensive brick because the app is suddenly gone from the store.
Oh, but they’ll allow you to keep already installed apps, so the only thing you need to do when you get a new phone is figure out which of your 100 apps have been unpublished in the meantime.
And then, I dunno, decide you are not going to upgrade because you don’t want devices in your house to be expensive bricks.
Not necessarily. I bought a very expensive cat toy robot that had a companion app. The company that made it didn’t just hide the app, they delisted it entirely. When I upgraded to a new phone, the download links were dead. It started me down a journey of coding my own replacement and reverse engineering the device’s firmware and BLE protocols which was a fun and rewarding experience. But, the fact that this was even necessary really stunk.
You can actually reinstall unlisted apps on a new phone They're available in the past purchase section. Not to defend Apple (especially since it's so hidden that very few users find it) but at least there's that.
And then, I dunno, decide you are not going to upgrade because you don’t want devices in your house to be expensive bricks.