Archived copies of printed newspapers are themselves a world of fascination for researchers. While digital archiving is taking place around the world, not everything is archived. I can go to a library and request newspaper files 50, 60, 70 years old, even older and research classifieds in them any day. I am not sure whether such such material is being archived. Letters to the Editor are also a very important part of the contemporary sociology and history of the newspapers time of publication. Considering the sheer volume of newspapers that have been and are being published it would be asking too much that digital archives of every single item published be available on newspaper web sites.
My two bits.