For me, the content created by communities that is exclusively available on that site is really helpful to me. If possible I would definitely try and archive a few subreddits and write something to search and access it offline (sorta like https://en.wikipedia.org/wiki/Kiwix but for reddit).
Yup, there was a subreddit for every little thing. Every show I’d watch, even fairly niche ones, I could go read the subreddit after. Can’t do that elsewhere really. Might happen with Lemmy in time, but not yet.