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
Many had and have multiple accounts due to federation shenanigans. The actual userbase might have actually grown despite significantly lower numbers compared to the peak.
It took me a while to find an instance that I liked. I'm sure I counted as multiple active users until recently.
In reality, I'm the same one human who has been accessing the same servers.