Where do you put those hard drives?
The protagonist had an Apple device. They don't have hard disk slots and usually have pretty small built-in storage.
Last time I tried, I found that iTunes cannot use removable storage because it blows up if it's not there. It was also incredibly difficult to get it to use a NAS drive, and I don't remember if I ever got that working.
Apple explicitly encourage you to use their "cloud" services instead.
So it's not just a hard disk. He'd need a very large, Apple-approved hard disk.
In a machine that was carefully Designed in California to be unable to have a large hard disk.