Purchased Apps Was Not Restored After Restoring from Backup

For more info about what is being backed up see About backups for iOS devices - Apple Support

"iCloud backups don't include:

• Data that's already stored in iCloud, like Contacts, Calendars, Notes, iCloud Photos, iMessages, Voice Memos, text (SMS) and multimedia (MMS) messages, and Health data*
• Data stored in other cloud services, like Gmail and Exchange mail
• Apple Mail data
• Apple Pay information and settings
• Face ID or Touch ID settings
• iCloud Music Library and App Store content (If it's still available in the iTunes, App, or Apple Books store, you can tap to re-download your already purchased content.)"

Managing apps using iTunes from a computer became impractical with the introduction of app thinning. That functionality was removed from iTunes several years ago.

Prior to its removal, after the restore was complete, the apps would be re-installed from iTunes. Now, they will be re-downloaded from the app store when the data has finished restoring.

You do not purchase a piece of software nor a particular release of a software. You purchase a limited use license for a developers software. And that developer can indeed, quite legally, choose to stop supporting their app, or any particular version of their app, whenever they choose to for whatever reason they decide. It’s in the terms of the license you purchased when you downloaded and paid for the software.

Legal - Licensed Application End User License Agreement - Apple

Apple has never included installers for apps in iTunes nor iCloud backups. Doing so would make most people’s backups huge, well beyond the default free 5GB iCloud account storage allocation. And they removed the ability to manage Apps in iTunes some time ago now. Even when it was available, many people never kept copies of their app’s installers again because of the disc space it required to do so.

Pointers to the apps in the app store are a part of your backup. If after a few days from restoring from backup and having device connected to wifi and power issue still persisted, then it might be that something went wrong with the process and trying again would be the solution.

If this was right after restoring then it is likely that apps, and other data, was still being restored and waiting would have been the solution.

Have a look at this support articles for more info:

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

"Content like your apps, photos, music, and other information will continue to restore in the background for the next several hours or days, depending on the amount of information there is. Try to connect often to Wi-Fi and power to let the process complete."

iCloud: Restore or set up iOS devices from an iCloud backup - Apple Support

"Your settings and accounts are restored from the iCloud backup you chose. Your device restarts and begins downloading your purchased music, movies, TV shows, apps, books, photos, and other content. If your device can’t download the version of an app that was backed up, it downloads the latest version."

I hope this helps

Apps have never been part of the backup. They must be re-downloaded from the app store (in app data is included in the backup at the discretion of the app developer). They will be re-downloaded as the final step in the restore process.

Your assumption was incorrect.

If the developer has withdrawn the app from the app store, there is nothing Apple can do about that.

bhenri wrote:

Apps are indeed a part of your backup.

No. They are not. Pointers to the apps in the app store are included. The apps themselves are not.

True, you're right! Sorry, I had a poor choice of words.

Corrected!