Lemmy just reached a new milestone: 1 million posts, across 1,323 servers.
Sports is definitely hard to have take off in these sorts of spaces, since sports are generally talked about much more amongst regular/casual users, than the more tech-savvy crowd who are willing to try these things out.
It’s the same on the biggest ActivityPub platform (Mastodon) - the really popular regular subjects such as sports and cars just don’t have a presence there.