I own a few SSDs, but for me, HDDs still make the most sense for the majority of my storage. It's not even close. High-capacity HDDs are half the price of high-capacity SDDs.
My HDDs tend to last longer than my SSDs, too. For bulk data storage that isn't being transported frequently, it's a no-brainer. For anything else, though, I think SSDs still have the advantage despite their shorter lifespans because of their better tolerance for physical impact and higher read/write speeds.
They can also be left unpowered "forever" without data loss, while SSD lose bits after a few weeks.
Really? Do you have some evidence for that?
I feel like this would be easy to test, at some cost. Buy N SSDs from X manufacturers. Fill the entire disk with random bits (/dev/urandom), read it back and compute a hash. Wait A, B, C, and D durations. After each duration, read the drives again and compare the hash.
Bit rot is definitely a problem with HDDs, especially as their bit densities increased. I've heard that bit rot on SSDs also became a thing as well after they started moving from SLC to MLC.
I'd be interested to see a study on how prevalent either of them are.
I recently powered up a 2012 Macbook Air with SSD after 7 years and had no data loss.
In addition to the cost advantage, HDD firmware is simpler and more reliable.