#for both myself and my friends
if you definitely 100% own all of the dnd 5E content after spending hundreds of dollars on it whether physically or digitally (or both!) u should use this site here as a quick n easy reference point for the content you definitely already legally own because you’re a law abiding citizen who has paid hundreds of dollars for a shittonne of books.
may I also add that if you accidentally misplaced your D&D books that you absolutely, definitely bought, you can find pdfs of them all here
and not just 5e, and not just D&D
and not just books, a few days ago I found an issue of a magazine that was published when I was two years old
but you know, very few people actually need this site probably because we all paid a hundreds of dollars for a shittonne of books.