None of the files in the 1997 tree have a file date anywhere near that old, the drive they are on wasn't created until decades later.

For me, there is only one durable, universally supported tag for those files, which is the folder structure. Due to the way cameras number photos, for any given photo file name, there are likely 5-10 other different photos with the same name.

You might be tempted to then call for a standard tag that would be supported, but what about files relating to things of unknown dates? Fossils, antiques, draft x of the Declaration of Independence, or of things planned in the future, with dates still in flux?

Having one canonical path and filename for a given collection of bits is a really effective tool, that I doubt will be surpassed any time soon.

However, the next best thing, in my humble opinion, is to use a cryptographic hash of the file in question, as Git does internally. You could map a filesystem interface to a data store based on Git, as long as you don't expect high speed writes to work with performance. (because new checksums require computing across the entire file, even if only 1 bit changes)