I have 3 different libraries, one for comics, one for TTRPG books, and my main one for actual eBooks. My main library is over 4GB with over 1,000 books.
No, I haven’t read all of them, but I am working on it. They have been collected over the last 15 years from Sony eReader store, Kobo books, Amazon Kindle, B&N, Archive.org and other Public Domain books hosts, Humble Bundle, Story Bundle, and various other places.
Largest categories are Sci-Fi, Fantasy, and Mystery.
I wish there was a way to link to an Android app.
I have on library stored on my NAS drive. It contains magazines and for the most part TTRPG books. Only about 200 in total. I run a calibre-web in a docker container and connect thru Tailscale using the Firefox browser so that I can just read what book I need based on what game we play. The magazines I access in the same way but on my phone when travelling.