And it's precisely what's responsible for falling HDD volumes and rising SDD volumes.

Which, in turn, is precisely what's responsible for stagnant HDD and falling SSD prices.

I can get a big-enough 480GB Sandisk SSD for $55 right now, and a 2TB SSD for $190, manufacturer direct. Looking at their WD_BLACK HDD, that's actually a buck cheaper than their 500GB HDD. For 2TB, I'd be looking at $99 instead of $190; at less than 2x the price difference, the SSD is a far better option for most people.

Of course, the HDD goes all the way up to 10TB (at $320), at which point, so it still comes out ahead for bulk storage. SSDs hit a breakpoint at 2TB, where price and complexity go up astronomically. I can either drop a few grand on a specialized product, or around $1000 on several drives and build a RAID. So there's still a market. Just not a particularly big one.

Prices are based on first sensible link on their web page (presumably, most popular product). You can go up or down in price if you click around, go off-brand, but the qualitative picture doesn't change. HDDs require a lot of infrastructure, and the market is evaporating.

I suspect the upper end will disappear soon enough.

I do still want some kind of bulk storage. I want to back up my photos somewhere reliable, but there seems little left. Tape is thousands of dollars for the hardware, while optical is now tiny. Nothing seems to compete with the volumes, economies-of-scale, or R&D budget of integrated circuits.