Number of (active) Lemmy users seems to stabilize and I think this is a great thing. Indeed we got a lot of users when reddit shutdown its API (I was among them despite being a long time oss user), many have left, but the community seems now to stabilize to ~ ½ of the big grow in june '23. I think this is very nice for lemmy, we can be proud of this project.
The stats come from: https://fedidb.org/software/lemmy
What defines an active user?
Up through Lemmy version 0.18.5, "active" meant posting or commenting within a specified timeframe (past month, past year, etc.). Starting with version 0.19.0 voting also counts as being active.
aka, the lurkers 👀
I've always upvoted both posts that are on topic to the community and always to people who take the time out of their day to reply.
It's like common courtesy to me and votes are like free confetti anyways.
So I suppose the OP's figures are, off.
I am uncounted, but next month I will be active!