Speculating here, but carbon dating is potentially one useful vector for protecting against forgery/manipulation. Conversely, once something is digitized, you cannot incontrovertibly authenticate the origin time of the relevant bit flips and you also introduce the (now seemingly just on the horizon) possibility of AI-optimized digital forgeries that are indistinguishable from originals. That's off the top of my head, but the OP may have further insight.