I read an article this morning about scientists warning of a digital dark age
with current digital media at risk of disappearing over time. I always thought optical media would last longer than magnetic if taken care of and not scratched up but they say otherwise. They mention synthetic DNA technology could be a solution for the longer term and that “A single gram of DNA could, in principle, store every bit of datum ever recorded by humans in a container about the size and weight of a couple of pickup trucks.”
This isn't anything new... just to give a real world example, when I was in college I used an Apple IIGS computer for just about everything... the OS and my utilities were all on 3.5" floppy disks. Over the time I owned that machine, I had several disks go bad... you'd pop one in and all of a sudden you'd get read errors or whatever. So I made a habit of duplicating my disks at the beginning of every semester, and always keeping spare copies of anything important.
Magnetic media can go bad... even optical can go bad. Flash can definitely go bad.
If you're really concerned about the data, there are relatively easy things you can do to protect it. The most obvious is to make copies. If you're worried about the data on an old HDD drive, put it on a new HDD drive. If you're worried that a flash will go bad, copy it to a new flash. If you're worried that a device is no longer going to be supported, copy it to a more recent device. While it's true that interfaces change, often in just a few years, they don't just suddenly go away; there is always some overlap. And the good news is that as technologies change, the trend is towards higher capacities and greater performance.
You can also let someone else worry about the details, as technologies change, by using cloud storage. Better yet, do both - keep your own copies and cloud copies.
In short, if you can't be bothered to take steps to protect your data, you risk losing it... but that's true no matter what medium you choose to keep your information. Paper copies can be destroyed; so can microfilm or the various other ways information is stored. With digital there is an additional twist in that the medium itself can degrade over time; but again, the solution is fairly straightforward; make copies.