and in turn, demand for storage is slowed by lack of need for storage.
The real question should be: Where's my 4K video? My 10-bit-channel images? My lossless audio?
Yes they are here but not nearly as common as content delivered in ancient formats from over a decade ago. For example go on a wallpapers subreddit, the vast majority is still in 8-bit 1920x1080 JPEG. Video is still mostly 1080. The leading music services still deliver in 2-channel lossy formats. And this is 2016.
Most of this I suppose is because of the general slowness of the internet and the usage caps in many areas of the world.
So maybe improve internet service -> create more detailed content and let people save it -> people will want to demand more storage to store all that in.