I just looked at the Rust code from https://github.com/LemmyNet/lemmy/blob/main/crates/api_common/src/community.rs
and it looks like you need to give it params to get what you need, i.e.
curl https://lemmy.blahaj.zone/api/v3/community/list?type_=Local\&sort=Active\&limit=50 | jq
Returns the top 50 local communities sorted by Active
Just started rewatching 13 ❤️ I wonder why I was obsessed as an egg 🤔