I cannot uninstall the iTunes

Deleting and reinstalling iTunes doesn't affect device backups, which are stored in a separate location from the app. See Locate backups of your iPhone, iPad, and iPod touch - Apple Support. You should also be able to delete unwanted backups from iTunes > Preferences > Devices.

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iTunes is a core component in macOS 10.14 Mojave. It isn't designed to be uninstalled. It will be updated as and when the system is updated. What is the issue that makes you want to uninstall it?

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