You'd be surprised how little of the niche pre-internet stuff is digitized. There are some exceptions (national-circulation newspapers, some English-language books), but it's a minority of what's been published.
People have absolutely no idea how niche things were - every city of moderate size (maybe a million?) had an independent computer magazine of some sort, some literally mimeographed pages stapled together, others flashy magazine quality productions.
And they had columnists and journalists and everything. Heady time.
And I'm not sure I can go online and find a complete set of Byte Magazine much less the Boston Computer Society newsletter or something even more niche.
Probably I could find a lot of stuff if I went to enough libraries but it certainly isn't all available and nicely indexed on the open web.
And they had columnists and journalists and everything. Heady time.