They can't make money off of them? It will get split up and youtube spun off and they'll have to cut costs. Some maybe deemed inappropriate in the future. We had Geocities, Usenet and other sites and companies which held content then disappeared. Archiving them might be nice? But what's easier to archive and index videos or text form?

One the other hand, books published over a hundred years are still here even though the authors and publishers may long be gone.