A large problem in archiving is actually the copyright law. Sites like sci-hub or Library Genesis do a great job in archiving scientific papers and books, but a

A large problem in archiving is actually the copyright law. Sites like sci-hub or Library Genesis do a great job in archiving scientific papers and books, but are illegal. Also archive.org is sometimes on the brink of legal/illegal, e.g. not all material that can be found on archive.org is really legal; though for lots of the formally illegal archived content, the copyright holders do not care or do not want to cause an outcry.