Yes, it’s true. In fact, I hear about it pretty much every day: digital information can be lost quite easily.
But that’s not an indictment of digital technology at all. In fact, digital data opens up more possibilities for data retention than it closes.
Digital can be lost easily, but then, so can film. Let’s use your example of an original photo.
If you think about it, that photo can be lost or damaged in any number of ways. Aside from scratches, fingerprints, and fading, there are bends, tears, and foxing on the edges. That’s why historians take such precious care of original material like that.
The problem is that the film picture is exactly one, and only one, original. If something happens to that, it’s gone. This is pretty much the canonical case of there being one and only one copy.
Now, you can make copies of physical photos, but it may take a bit of effort and time, and the copies – no matter how good – are never quite as good as that original. You also have to physically store it (in an album or a box).
The digital copy of your original digital photographs can be duplicated for backup and other purposes easily and quickly. It’s also more likely to be saved or converted to new file types – as long as you remember to copy the file off that old 5¼-inch disk when new technology comes along.
In the end, your argument is about backing up. Too many people don’t back up, lose precious data, and blame the technology. Fortunately, digital records give us more opportunities to protect and keep precious memories safer than ever before.