How could it happen (English)

How could Power Point slideshows be forgotten?

At the Library of Congress and the Internet Archive? 
There are 80 million members In Slideshare and Teachers Pay Teacher and members have created several million slideshows. But none have ended up at the Library of Congress.

Maybe some are at the Internet Archive, but mostly since Anders Dernback started adding his slideshows. Finding the evidence is easy. One searches in their search function and the Library of Congress doesn't have a single slideshow. The slide shows are at least 40,000 years old and have been found on cave walls with wild boar hunting motifs.