I hope it will not harm the device of the phone
I hope I’m very safe operating on my device
iPhone 6, iOS 12
Question marked as
IOS 12.5.4 is completely safe and is upgraded by millions of people. Make sure before upgrading you should uninstall apps that you feel aren't safe.
You can read more about this update from the official page https://support.apple.com/en-us/HT212548