> our eroding right to control our own devices.

If you want to frame this as an ideological debate over freedom of user choice, instead of a very specific debate about a very specific App Store rule (even though the latter, and not the former, is what the email in the OP is about), then sure: you have the choice to select a device with a tightly-controlled ecosystem. You also have the choice not to. It was your choice to obtain this device, knowing full well that it would be tightly controlled. Or if you didn't know, you also have the right to return the device and no longer use it.

> the missing alternatives to the App Store on iPhones

Get an Android phone and use the Play Store (or any of the 3rd party Android stores). The magic of a smartphone isn't only on iPhone and there's nothing you can do on iPhone that you can't do elsewhere.

Third party app stores on Android are purposely hindered in their functionality by Google. Restrictions in Android mean that they cannot install apps in the background, autoupdate apps or batch install apps. The Play Store can do all of those things, however.

Apple and Google have an effective duopoly on the mobile and tablet app distribution markets.

Let me know when you find a decent alternative to Hindenburg [1] that work as well and that field reporter might want to actually use on Android.

[1]: https://hindenburg.com/products/hindenburg-field-recorder

There are a lot of opinions packed in your description of the app - I'm sure there are apps that meet reasonable bar for replacement.