Clock

The Clock app is not one of the apps you can delete:

Delete built-in Apple apps on your iOS 12, iOS 13, or iPadOS device or Apple Watch - Apple Support

However, there is nothing that says you have to use it. You can download and use whatever clock/alarm app you want from the App Store.

Don't use it, the choice is yours.

You can't delete the following Apps from the iPhone

Photos, Camera, Clock, App Store, Health, Wallet, Safari, Phone, Message & Find My apps.