That was my point; almost nobody is storing HD series anymore because people want to (and in many cases legally are only able to) stream them instead.
They never were. Why would you store a movie on a hard drive after you watched it?
Flac music can fill another 500 GB easily, more depending what you listen to..
Not a lot of people know how/can stream a properly good 1080p stream with high bitrates. oh, you want some subtitles because you're not an english native? Or you have fancy stereo/surround setup that you want to actually use? oh well, you better download some bigger version.
But if the Cloud is made up of hard drives, then hard drive manufacturers still win. Look up "Backblaze Pods" if you don't believe me.
I mean, if everyone just stores data in the "Cloud", its mostly composed of hard drives anyway. You just no longer own or maintain the hard drive.
If drives in the Cloud are, on average, utilized more efficiently (both in terms of less unused drive capacity being purchased, and existing drives being used for more of their design life and not being tossed because the device they are in is end-of-life even if the drive isn't) than traditional locally-deployed (both client and server) drives, then increasing cloud use could mean the manufacturer's still lose (in terms of year-over-year sales) even with total storage increasing, if the increase in average efficiency outpaces the increase in storage, so that annual drive sales drop.
Because we're seeing, at the same time, a drive away from owning media and instead streaming them, and/or storing data increasingly in The Cloud® and only having a small working set locally.
All those off-loaded will have to be stored somewhere by someone, and that someone will most likely keep using spinning rust for its better price.
And if you do want to keep all your data locally (e.g. because you're living in Nowhere Innawoods and ISPs struggle to get you 6 MBit/s), HDDs can't keep getting bigger and cheaper fast enough.