Hopefully there were copies off-site.
Paper documents still exist mainly for the purpose of legal proceedings. In fact, paper was invented 2,000 years ago for that purpose. The FIB raiding Trump's paper document storage is all about fighting Trump's lawsuits. The FIB has long operated as a lawless criminal organization.
It's unlikely any White House paper documents still exist as single copies. Trump may have kept a few paper originals, but it is unlikely there aren't digital copies of everything.
Fedzilla is very afraid of Trump, a credible threat to their lucrative monopoly on violence. It's not that Fedzilla doesn't already have copies of all the documents; it's that it doesn't want Trump to also have them.