You’re in luck, I just modified the instance crawler on join-lemmy.org to collect statistics for all Lemmy instances. You can find them in this repo in JSON format. Now we need someone to build a tool that can visualize it. The stats could even be shown directly on join-lemmy.org.

Fedidb does that for instances, but not individual communities. Might be easy to add though.

can you elaborate?

Most stats are at the instance level, rather than the community level, because indecipherable fediverse technobabble. Here’s lemmy, piefed, and mbin

Doesn’t Mbin measure this for communities you moderate?