Entirety of the main PD ebook places in the main formats gets you to nearly 500,000 items.
Then there are PDF manuals, datasheets, service info, old magazines, scans on wayback machine, websites converted.
See
http://www.americanradiohistory.com for technical magazines in UK ones since 1920s.
Hmm, now that I've got fibre and Unlimited is now really 3000 Gbyte instead of 350 GByte per rolling 30 days…
It's a bit mad and being immortal would be a help in consumption, but we can't assume piracy.