That absolutely destroys interoperability, and is not a good thing. If the program that generated a file must give permission for it to be accessed, then a proprietary program can prevent interoperability simply by not actively enabling it.
Passing information between programs must be in the control of the user, not a program.
Actually android do exact the same thing these days. So you sometimes see 'XXX app want to access your photos', or a file explore to select which directory you grant for app to access.
There used to be a loop hole that any app can read sd card. But it is also sealed since android 10. Now every app see different rootfs.
> then a proprietary program can prevent interoperability simply by not actively enabling it
These doesn't really matter, a proprietary program can always break interoperability as long as they want. Did you see the old ms word .doc format? Even other version of ms word can't read it correctly, let alone any third party programs.
On iOS this can’t happen, regardless of whether an app was downloaded from the App Store or elsewhere.
AKA, a "computer."
My computer.
Today, iOS has a strong sandbox where apps can’t access data of other apps unless explicit permission is granted (eg. access your location/contacts/photos), and apps can’t access or modify system files at all.
Also consider that sideloaded apps does not mean allowing unvetted apps - Apple could still mandate macOS-style app notarization to prevent malware:
> Notarization is a malware scanning service provided by Apple. Developers who want to distribute apps for macOS outside the App Store submit their apps for scanning as part of the distribution process. Apple scans this software for known malware and, if none is found, issues a Notarization ticket. Typically, developers staple this ticket to their app so Gatekeeper can verify and launch the app, even offline.
> Apple can also issue a revocation ticket for apps known to be malicious—even if they’ve been previously notarized. macOS regularly checks for new revocation tickets so that Gatekeeper has the latest information and can block launch of such files. This process can very quickly block malicious apps because updates happen in the background much more frequently than even the background updates that push new XProtect signatures. In addition, this protection can be applied to both apps that have been previously and those that haven’t.
https://support.apple.com/guide/security/protecting-against-...