I’m going to miss r/datasets, r/selfhosted and other subreddits that allowed me to tap into accessible niche knowledge. I’m sure there are subs I had not yet discovered, but a lot of the information they collected over the years may be gone. I hope those communities will find their way to Lemmy and rebuild.

FWIW, selfhosted does have a sort of “best of” list on GitHub at: https://github.com/awesome-selfhosted/awesome-selfhosted