512GB is the ultimate storage at this age. I can fill it with several movies, tv shows, etc which I can enjoy whenever WiFi or cellular connection is not available or off line As you know, free WiFi is hackable. The extra storage can be used for other emergency things also. There is never too much storage, which makes its usage longer.
Below 512 GB can be useful but at some points, it has its limits. 64, 128 and 256 GB are ancients and obsolete. You will see what I am saying eventually especially when the technology is getting more advanced. iCloud is helpful but not helpful when there is no WiFi or cellular connection. Free Wifi cannot be relied on the security due to extremely vulnerable risks of getting hacked when you use it.
512 GB is also the first highest storage in the iPhone history. Having it is a pride for all of us who are fortunate to be able to have it.