[mholt]

_> So now you have a big folder with many zips, and maybe some extracted folders, because things happen over the years, etc._

Oh, right.

Timelinize can do that. Takeout all your data, then import it into Timelinize. Then delete your Takeout (after Timelinize is finished and stable, of course, heh). Then next time you Takeout, just import it all into Timelinize again. (It de-dupes!) Then delete the Takeout, etc. (Maybe Timelinize can do the cleanup for you someday.)

The de-duping depends on the item being recognizable. Best if the data source provides an ID. Otherwise, things like certain metadata and content can be used to determine duplicates.