Majority of users do not need to be doing this though. I'm all for helping folks with 0KB left, but if you don't know why step 3 of this process is essential, you could really mess things up for yourself.

Just to clarify, if your device's date/time is that far out of sync and you're trying to log in, you could get an account locked just as a security measure. Every app trying to do that? Yeah, "system data" wouldn't be your biggest problem anymore.

How would they with this complicated procedure. Apple should just add a "purge cached items" button within the storage section in settings. They can then explain what it does and what could be deleted. They do it on MacOS.

Know or need.

Been using iPhones since 3G and have never once totally run out of storage.