With 100 years you need every other generation to rewrite/refresh them, or the data is lost.

For things recorded today, nobody will care about refreshing for 75 heads, and if during 2100-2125 there are some budget constraints/wars/whatnot, the data will rot.

With 1000 years, you can just throw stuff into a bunker and all that it will take will be for someone in a period of 2800-3025 to take the time to refresh the library. 200 years should be enough to wait through a mild civ collapse or something.

Sure we’re talking about times beyond our lifetimes, but a lot if things we are sorrounded by were planned by people who knew they wouldn’t live to see the outcomes.