It's not only storage. I think most will be fine after 30 years. The problem is often: how are you going to read it after all those years? I got floppy disks

It's not only storage. I think most will be fine after 30 years. The problem is often: how are you going to read it after all those years? I got floppy disks that are ~25 years old. But without an old USB disk drive there is no way to know if they still are readable. And if USB-C becomes the norm I am not sure if I can read them ever again.