Just my $0.02 Back in ~2020, the only Lemmy instances which had activity were the ones that people flocked to when their Subreddit was shutdown. It went something like:
1 - Group sets up a hateful Subreddit 2 - Group members begin to repeatedly violate Reddit’s TOS 3 - Reddit bans the Subreddit 4 - Some groups had enough cohesion to send their subscribers to a Lemmy instance to try and salvage the situation
As a result, when I joined the Mastadon Fediverse in 2021, I heard the rumors about “Lemmy is only used by people who were banned by reddit. That’s why it’s only Tankies there.”