That's why every semi-decent storage system based on flash should use some sort of B trees with copy on write updates and timestamps on every revision of the superblock so you know which is the latest one. IMO it should be possible to build a bulletproof flash drive and some SSDs are known to handle power loss well, it's just that many cheap ones either don't bother or are buggy.
Exactly – although B-trees aren't the only option; there are a lot of
known-good methods –; it's that because the memory controller is usually implemented in silicon, it (and the associated passives that cost next to nothing) is an attractive choice for cost-cutting.
Some use heuristics (to avoid storing the number of block writes, saving memory), and depending on the filesystem (block patterns), can die very quickly because of superblock updates hit the same physical flash blocks exhausting them. But, because it is dependent on the filesystem, users blame the filesystem (for being "bad" on flash media), instead of the wear leveling. This is particularly common among people who have high brand awareness, and consider the flash manufacturer more reliable than e.g. open-source software (open sores, they often call it), as non-Windows/non-Mac filesystems are rarely even considered by the manufacturers, but widely used on (especially embedded) devices based on Linux, Minix, or BSD variants. They believe that if the device wear leveling behaves well on FAT/exFAT, it must be the software's fault if it dies rapidly on any other filesystem (or in raw block use, without any filesystem at all).
(Compare to e.g. Apple devices liquid sensitivity, which Louis Rossmann often talks about. Most other laptop/tablet boards are not nearly as sensitive to tiny amounts of moisture, because it is easy and cheap to achieve. For Apple, it is an internal design choice, extending to color-changing moisture detection stickers on their boards... Stuff like putting 24V backlight power next to a logic pin going directly to a low-voltage processor in a connector prone to moisture and dust ingress, near the display hinge. There is no technical reason to do that, if the same connector has half a dozen ground pins just a mm or two away.)
We've seen effects of similar cost-cutting on the spinning rust side, too. While WD drives have a good reputation, they have quite a few series that had serious issues with RAID, or performance in general; things that they disclosed later only because users were too upset (upset enough to harm their brand if they did nothing).
I fully know there is no technical or technological reason for the weaknesses I've claimed in this thread; it's just stupidity or cost-cutting.
Starting from the beginning again. What exactly are you trying to do/achieve and/or find out ?
Very good point.
I personally was kind-of assuming the underlying question was something like "if I download a file, is it possible a spinny-disk HDD manufactured after 2000 stores it in blocks that turn out to be bad?"
The answer is yes and no. No, because the drives do not knowingly store anything to the blocks it knows to be bad. Yes, because while the block may be considered good when the data is written to it, it can be detected as bad when trying to read the data later on. SMART reports these as 'uncorrectable errors'. Heck, the block might be good at that time, but the media surface degrade later on (physically or magnetically, for whatever reason from manufacturing issue to temperature gradients to radiation damage) becoming 'bad'. This applies even if there happens to be a drive that knows nothing about bad blocks or sector reallocation.
There is a technology that detects blocks going bad by analysing the error correction frequency (amount of bit errors corrected with ECC data), and reallocates the block before any data loss happens. (This is described in a patent I linked to earlier.) However, we don't know which, if any, drives implement this; I think most manufacturers would consider this "too costly", wrt. to their profit margins.
Actually, I'm finding too many (assuming there are many more out there, I didn't find). It seems suspiciously like spamming or other bad stuff.
That reminded me of certain efforts of renaming "daemons" used in Unix systems to "angels" or "agents", and similar more recent efforts wrt. "master" and "slave"... Perhaps some people just have too much idle time right now?