Re: "How to restore missing Maps app icon on iPhone 14 Pro Max?"
The maps icon may have just been removed from the home screen without being deleted.
Try searching / looking again in the App Library (swipe left past your last home screen).
If the icon is there, touch and hold the icon and slide it left back to the home screen.
See Apple Support's Tips for what to do:
If you can't find an app on the Home Screen on your iPhone - Apple Support
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Re: "I can’t even delete it from settings to force a new download".
See the article below for how to delete and restore a built-in app from your device:
(Important: If you delete(d) the Maps app it won't be available to use with CarPlay)
Delete built-in Apple apps from your iPhone, iPad, or Apple Watch - Apple Support
You can double-check whether Maps was deleted / is available to re-download:
Eg: article above says:
"Restore a built-in app that you deleted
- On your iPhone, iPad, or Apple Watch, go to the App Store.
- Search for the app. Make sure that you use the exact name of the app.
- Tap the Redownload button (icon: blue cloud with down arrow).
- Wait for the app to restore, then open it from your Home Screen."