It's got about 17,000 titles globally [1]. If they have copies in SD, 720p, HD and 4k that would be 68,000 versions (plus some extra audio tracks for stuff dubbed in multiple languages, but I suspect this is fairly minimal in terms of storage though)
Let's assume that the resolutions have the bitrates at 5, 10, 15 and 20 mbps.
The average length of a Netflix original movie is ~90mins [2]
So that would require about 575TB in storage if I have done my maths correctly.
You would need about 20x30TB Kioxia CD6 SSDs for all that. Very expensive but definitely technically possible.
I could totally see it being possible to fit those drives in a single node to push the 800gbps required, not increasing the over rack requirement at all. Not sure if the bandwidth from that many drives is enough, might have to cache some of the most watched stuff to ram)
Not gonna see any in home boxes with all the titles pre loaded any time soon though. As a hard drive array that's still 30x20TB drives.
[1] https://www.comparitech.com/blog/vpn-privacy/netflix-statist...
[2] https://stephenfollows.com/netflix-original-movies-shows/#:~...)