Cloud does not work. If you have an app that is no longer available in the App Store, when you install from a backup you are out of luck because that app can’t be downloaded from the App Store.
If you choose to manage your phone from a Mac, then you can save a full backup.
It's not a binary choice: you can do a full local device backup occasionally and still use iCloud. That way you'll have saved copies of old apps available in case they get discontinued on the app store.
If you choose to manage your phone from a Mac, then you can save a full backup.