“However, does anyone still have digital photo files they took in 1996 or 2002?”
I was a bit late in coming to digital cameras, having a large investment in Olympus OM2 cameras (yes, two). That said, I still have all my prints and all my negatives. I must scan them some day.
I went digital late in 2004. I still have all the originals from then onwards. This is Goolara Peak: we are going down a slightly steep spur off it to the Coxs River below.

My secret for this, if it can be called that, is simple: BACKUPS, every night.
On a PC I use Second Copy, a professionally written backup system which is so far better than some of the glossy freebies it is not funny. Every night Second Copy automatically runs through my entire disk and makes a backup of any new files it finds onto a second independent hard disk within the box. Actually, it makes two backups: one is simply incremental and the other is an image. EVERY night, automatically. And the hard disk is in standard PC disk format: it can be read on any PC directly.
Then every week or two I plug in a USB-connected stand-alone hard drive and run Second Copy onto it. I have two of these stand-alone hard drives. They are of course immune to power failure damage. I did try a Maxtor Network-Attached Storage (NAS) RAID system once, but the controller died and the disk contents became inaccessible. The disks were partly encrypted, which was incredibly stupid. I had them recovered by a professional firm. Cost $$.
I have thousands of photos on file. I simply could not remember every one of them without seeing them. But the memories …
Cheers