aside from stuff like annas archive / libgen in the past, i had ok luck using dht search sites like bt4g ~org~ but it was very hit and miss in terms of whether the torrent/magnet still had seeds. but that approach did have some collections like what you mentioned. i havent really done it that way in a long time so not sure how well it works these days tho… like I searched a couple things similar to what you had in the OP and did get some small number of results (less than 1 page). some of those appeared valid but watch out cuz there were also some obvious malware ones that were like .exe. Probably not the best way to do things for 2026+ … could also check fmhy.net/reading but i suspect most of those are also going to be geared more towards individual books than collections